Information technologies in professional activities. Mikheeva E.V. Information technologies in professional activities: A short course of lectures

Human society has come to a point where information and its sources have confidently entered everyday life, because it is impossible to imagine even a second without a flow of information data.

It is no secret that information is quite expensive, which is confirmed by the transition of a large number of workers from the production sector to the information sector.

Over time, the concept of “information” began to acquire the connotation of modern high technologies and developments, which led to the appearance of the abbreviation “IT” - information technology. The use of information technology is an integral process of everyday life, regardless of whether we are talking about leisure or work. To understand the importance of IT today, let us turn to the concept of this phenomenon.

Information technology is a set of measures, methods, technical means, information and production processes, which ensure constant collection, storage, processing and output (display, forwarding) of information.

Informatization of society leads to the internationalization of production. The foreign trade balance of relevant professional knowledge serves as an indicator of the technical power of the state, and this is what the concept of information technology is associated with. It is implemented through the market for licenses of industrial products, various know-how, as well as consultations on the use of high-tech products.

Thanks to the evolution of the global market, a country that is engaged in the sale of knowledge-intensive products, including modern professional knowledge and the latest technologies, has an advantage. There is an active trade in an invisible product in the form of knowledge, culture, and stereotypes of behavior are actively imposed. This was the reason why in information society information, creativity and knowledge act as a strategic resource. And since talent is not created, there is a need to create a culture, that is, an environment in which talent can develop and flourish. The influence of computer technology is enormous here, expressed in distance learning, computer games, and videos.

The purpose of the information system is to store, search and provide data upon requests from users. For example, the essence of an economic information system is the processing of relevant information. The subject area here is statistics, accounting, insurance, credit and financial, banking, as well as other types of commercial activities. To use an economic information system in the workplace, it must be designed using information technology. This could be electronic office, email, spreadsheet and word processors and so on. The trend of creating information technologies accessible to users continues.

It turns out that the workplace uses both information technologies in the economy, which are developed by designers, and information technologies, which make it possible to automate activities in one’s workplace.

State policy in the field of use of information technologies is designed to create the necessary conditions to ensure consistency in the actions of federal government bodies in the formation and implementation of informatization programs and projects.

As can be seen above, IT covers all areas of our daily lives and is an integral part of almost any process and relationship. Summarizing the above, we have come to the logical conclusion that the use of information technologies in various fields and industries makes it possible to broadly classify the knowledge available about them, which allows us to highlight their main directions: production and business, research and scientific-technical, cultural, entertainment and educational .

The classification of information technologies helps to determine the most active areas of implementation and use of IT: increasing the level of public awareness of modern information resources; increasing production efficiency and various works by introducing automation and optimization information processes; increase in active information relations between people; development of educational systems and cultural awareness; intellectualization of society. In any case, the basis of all processes is information - the exchange of information and data between objects of relations (people, devices, etc.). The standard of living and work efficiency depend on the effectiveness and quality of such interaction for data exchange.

Types of professional information activities human using technical means and information resources.

Human activity associated with the processes of receiving, transforming, accumulating and transmitting information is called information activities.

Nowadays, computers are used to process not only numbers, but also other types of information. Thanks to this, computers have firmly entered the life of modern people and are widely used in manufacturing, design work, business and many other industries.

But to modern technical means working with information includes not only computers, but also other devices that ensure its transmission, processing and storage:

· Network equipment: modems, cables, network adapters.

· Analog-to-digital and digital-to-analog converters.

· digital photo and video cameras, digital voice recorders.

· Recording devices (CD-R, CD-RW, DVD-RW, etc.).

· Printing equipment.

· Digital music studios.

· Medical equipment for ultrasound and tomography;

· Scanners in archives, libraries, shops, exams and polling stations;

TV tuners for feeding TV signal to the computer.

· Plotters and various printers.

· Multimedia projectors.

· Flash memory, also used in players and cameras.

· Mobile phones.

In addition to personal computers, there are powerful computing systems for solving complex scientific, technical and defense problems, processing huge databases, and operating telecommunication networks (Internet):

· Multiprocessor systems for parallel data processing (control of complex technological processes).

· Servers in a global computer network that manage work and store a huge amount of information.

· Special computers for design and engineering work (design of aircraft and spaceships, bridges and buildings, etc.).

All of the listed technical means and systems are designed to work with information resources (IR) in various sectors of the economy.

There are several main areas where information activities are related to computers.

1. Scientific research. Calculations and calculations are an obligatory element of those scientific studies where it is necessary, on the basis of an experiment, to build a hypothesis about the patterns manifested in it. Special automated systems for scientific research. Computational operations on a computer are performed not only by mathematicians, mechanics, physicists, and astronomers, but also by specialists in the field of economics. Literary scholars use special programs to analyze the texts of works and create various dictionaries.

2. Creation of new products. Some stages of creating new products can be automated, and therefore, it is not surprising that the computer has a place here too. Computer-aided design (CAD) systems are used in all design and engineering organizations. After all, integrated circuit It turned out to be possible to construct thanks to the computer itself and its software. The designer enters technical specifications into CAD, and the use of databases, calculation blocks, expert systems, and a simulator makes it possible to obtain technical documentation from which prototypes will be manufactured.

3. Management. The theory of automatic control at the time of the creation of computers was a well-developed exact engineering science, so it turned out to be possible to use computers for control purposes. Automatic control systems (ACS) can control processes for which mathematical models and methods for their solution have been developed. CNC machines program controlled(CNC) have a specialized computer with an operator console, display and keyboard, as well as control program. It indicates everything necessary to turn the workpiece into a part, the dimensions and shape of which are determined by the drawing. Automatic washing machines, microwave ovens, sewing and embroidery machines, etc. operate under special programs.

4. Information systems (IS), databases (DB). The basis of the IP is a data bank, which stores large amounts of information about any area of ​​​​human knowledge. This could be information about the city’s infrastructure (transport, map, telephones, organizations, etc.). The use of the Internet makes IP information available to a large number of users. Currently, Moscow schools have access to the Internet and can use information from various information systems to carry out projects in various fields (geography, history, literature, biology, ecology, etc.). IS or databases of institutions, schools, libraries, etc. allow you to perform searches, queries, changes and additions quickly, with a small number of errors and human resources.

5. Training. Computers have become widespread in the field of education. One of the most important goals of creating a system of educational portals is to explicitly form and with the participation of specialists a professional zone and mechanisms for searching for high-quality educational information.

6. Computers in publishing. The computer can be used by the author already at the very first stages of creating literary, journalistic and other works. Then the editor of the publishing house works with this text.

7. Automated workplace(ARM). Currently, this is a worker’s place, equipped with a computer and other technical means (printer, scanner, audio speakers or headphones, microphone, video camera, electron microscope, etc.). The workstation can also have access to the Internet, which allows you to quickly find the necessary information in your field of activity, receive and send emails, shop online, order electronic tickets etc.

Information resources that support certain professional activities are concentrated in arrays of documents, which in the modern version are prepared for automatic processing and stored in databases (DB), knowledge bases (KB), which, in turn, are part of some information system.

Let's try to describe in the following table the types of professional information activity of a person and the technical and information means that accompany it.

A person’s professional activity is in close relationship with software products and information technologies, since they make the work of a specialist comfortable, fast and most effective. Today, every professional activity is carried out on the basis of a software and hardware environment. The more modern information technologies are used in professional activities, the more efficient and productive the labor process.

Information technologies in professional activities Software products and information technologies make it possible to ensure reliable and safe operation for both computer equipment and the employee’s information system. They allow for high-quality and efficient processing, sorting and storage of necessary information and work data, and help facilitate the functions of an employee by automating certain work processes. Today, the activities of economists, managers, accountants, agents and other specialists are automated. The number of automated jobs is increasing every day, as automated processes allow you to carry out professional activities more accurately, clearly and quickly.

Firewall Firewall A firewall is a system or combination of systems that allows you to divide a network into two or more parts and implement a set of rules that determine the conditions under which packets can pass from one part to another. As a rule, this boundary is drawn between the enterprise local network and INTERNET, although it can also be drawn within the enterprise local network. The firewall allows all traffic to pass through it. For each packet that passes, the firewall decides whether to allow it or discard it. In order for a firewall to make these decisions, it needs to define a set of rules.

Packet Filters Firewalls with packet filters decide whether to allow or discard a packet by looking at IP addresses, flags or TCP port numbers in the header of this packet. The IP address and port number are network and transport layer information, respectively, but packet filters also use application layer information, because all standard services in TCP/IP are associated with specific number port. Tables are compiled to describe the rules for passing packets.

Application level servers Firewalls with application level servers use servers for specific services - TELNET, FTP, etc. (proxy server) running on the firewall and passing through all traffic related to this service. This creates two connections between the client and the server: from the client to the firewall and from the firewall to the destination.

Application level servers Using application level servers allows you to solve an important problem - to hide the structure of the local network, including information in the headers of mail packets or Domain Name Service (DNS), from external users. Another positive feature is the ability to authenticate at the user level (authentication is the process of confirming the identity of something; in this case, it is the process of confirming whether the user is who he claims to be). The most common servers are for the following services: terminals (Telnet, Rlogin) file transfer (Ftp) email (SMTP, POP3) WWW (HTTP) Gopher Wais X Window System (X11) Printer Rsh Finger news (NNTP), etc.

Connection-level servers The connection-level server is a TCP connection translator. The user makes a connection to a specific port on the firewall, which then makes a connection to a destination on the other side of the firewall. During a session, this translator copies bytes in both directions, acting like a wire.

Connection-level servers As a rule, the destination is specified in advance, while there can be many sources (one-to-many connection). Using different ports, different configurations can be created. This type of server allows you to create a translator for any user-defined TCP-based service, control access to this service, and collect statistics on its use.

Conclusion Conclusion The positive qualities of packet filters include the following: relatively low cost flexibility in defining filtering rules small delay in the passage of packets The disadvantages of this type of firewall are the following: the local network is visible (routed) from the INTERNET packet filtering rules are difficult to describe, very good knowledge is required TCP and UDP technologies if the firewall malfunctions, all computers behind it become completely unprotected or inaccessible authentication using an IP address can be deceived using IP spoofing (the attacking system impersonates another using its IP address) there is no authentication at the user level

Conclusion Conclusion The advantages of application-level servers include the following: the local network is invisible from the INTERNET; if the firewall fails, packets stop passing through the firewall, thereby creating no threat to the machines it protects; application-level protection allows large number additional checks, thereby reducing the likelihood of hacking using holes in the authentication software at the user level, an immediate warning system about a hacking attempt can be implemented. The disadvantages of this type are: higher cost than for packet filters; inability to use the RPC and UDP protocols; performance is lower than for packet filters.

LECTURES ON DISCIPLINE
"INFORMATION TECHNOLOGY
IN PROFESSIONAL ACTIVITIES"

Table of contents

Lecture 1. Information systems and the use of computer technology in professional activities

Informatization is gradually becoming the core, basis and technological foundation of civilization.

Why are we now talking about informatization as a special factor in the development of civilization? The answer to this question lies in the steady increase in the role of information processes in the life of society. Today, information has turned into a strategic resource of humanity, the only one of all resources that, when consumed, does not decrease, but increases.

The information revolution is absorbing more and more new areas of human interest. The computer has become a kind of epicenter, the core " information revolution».

The study of any discipline begins with definitions of basic terms and formulation of concepts. By the 21st century, the concepts of information and information technology have become established.

1.1. Basic concepts and definitions

The term "information" has many definitions. Initially under information (lat. informatio - explanation, presentation) understood information transmitted by people in various ways- verbally, using signals or technical means.

Nowadays, information is a general scientific concept that includes the exchange of information between people and machines, the exchange of signals in the plant and animal world, the transfer of characteristics from organism to organism, from cell to cell.

Basic concepts, definitions and terms are formulated by GOST 15971-90 “Information processing systems. Terms and definitions".

Information - This is information about facts, concepts, objects, events and ideas that have a specific meaning in a given context. Information is not just information, but necessary information that is important to the person who has it.

When defining the concept of information, you can start from a schematic representation of the process of its transmission. Information message associated with the message source (transmitter), receiver (receiver) and communication channel. Then information will be understood as any information that is the object of storage, transmission and transformation.

Along the same terminological line with the concept of information are the concepts of “data” and “knowledge”.

Data - this is information presented in a form suitable for processing by automatic means with possible human participation.

Knowledge - This is information on the basis of which certain conclusions can be drawn through logical reasoning.

Basic requirements for economic information:

Accuracy determined by the degree of proximity of information to the real state of an object, process, phenomenon.

Credibility. Information is reliable if it reflects the true state of affairs.

Efficiency reflects the relevance of information for necessary calculations and decision-making in changed conditions.

Completeness. Information can be called complete if it is sufficient for understanding and making decisions.

Important characteristics of information are its structure and form. The structure of information determines the relationships between its constituent elements. Among the main forms we can distinguish symbolic-text, graphic and sound forms.

A computer is a digital device. Any information, once “inside” a computer, be it programs, text documents, photographs or music, will exist in so-called digital form. This is a consequence of the fact that a computer only works with information if it is digitized. The computer converts information into digital form independently, and the user does not notice it.

People use to write numbers various systems Reckoning. The number system shows by what rules numbers are written and how arithmetic operations are performed on them.

In everyday life, we use the decimal system for writing numbers, when a number is written using ten digits (0, 1...9). To count time in hours, the duodecimal number system is used; in minutes and seconds, the sexagesimal number system is used. And this does not surprise any of us.

The computer uses the binary number system to record numbers, i.e. any number is written as a combination of two digits - 0 and 1. Why? Just binary numbers The easiest way to implement it technically is: 0 - no signal, 1 - there is a signal (voltage or current).

Both decimal and binary number systems are positional, i.e. the meaning of a digit depends on its location in the number notation. The place of a digit in a number is called the digit, and the number of digits in the number is called the digit of the number. The digits are numbered from right to left, and each digit corresponds to a base degree of the number system.

The minimum unit of information in computing is 1 bit - information defined by one of two possible values ​​- 0 or 1. In practice, a larger unit of information is used - a byte.

Byte is the information contained in 8-bit binary code:

1 byte = 8 bits.

To store large amounts of information, derived units of measurement of its quantity are used:

1 KB ( kilobyte ) = 1024 bytes = 2 10 byte;

1 MB ( megabyte ) = 1024 KB = 2 10 Kbyte;

1 GB ( gigabyte ) = 1024 MB = 2 10 MB;

1 TB ( terabyte ) = 1024 GB = 2 10 GB.

Any information processed by a computer is encoded, i.e. is represented as a numeric code. How is information encoded? Let's consider the presentation of text information.

To represent information in a computer, an alphabet with a capacity of 256 characters is used. One character of such an alphabet carries 8 bits of information: 2 8 = 256. Consequently, the binary code of each character in a computer text occupies 1 byte of memory.

One byte can store 256 different numbers (from 0 to 255). In order to encode uppercase and lowercase letters of the Latin alphabet, 52 numbers are needed, and another 66 numbers are needed for the Russian alphabet. In addition, you need to code various signs punctuation and special characters. A table of such encoding is called an ASCII table. Its first half is used to store the Latin alphabet and special characters, and the second half contains pseudographic characters and letters of national alphabets.

Performance graphic information relies on the representation of the monitor screen as an array of color dots (pixels) of M×N size. Each pixel has its own color, represented as a combination of shades of the three primary colors: red, blue and green. In order for color rendition to be close to real, at least 256 shades of each color are required.

During the process of encoding an image in a computer, it is spatially discretized, i.e. splitting a continuous graphic image into separate elements, with each element of the image assigned a specific code.

It is also possible to encode in binary form audio information. During the encoding process of continuous sound signal The sound wave is split into separate small temporary sections. Moreover, for each such section a certain amplitude value is set. The process of breaking up a sound wave is called time sampling.

1.2. Information systems and technologies

The concept of “information system” appeared in connection with the use of new information technology based on the use of computers and communications.

Information system(IS) is a communication system for collecting, transmitting, and processing information about an object, supplying an employee of any profession with information to implement the management function. In other words, an information system is an ordered collection of documented information and information technologies.

Like every system, IS has the properties of divisibility and integrity.

Divisibility means that the system can be represented from various independent components- subsystems The ability to isolate subsystems simplifies the analysis, development, implementation and operation of the IS.

Property integrity indicates the consistency of the functioning of subsystems in the system as a whole.

Depending on the level of automation, manual, automated and automatic information systems are distinguished.

Manual Information systems are characterized by the performance of all information processing operations by humans. IN automated IS, some of the control or data processing functions are carried out automatically, and some are carried out by humans. IN automatic IS all functions of management and information processing are performed by technical means without human participation.

The information system includes the information environment and information technologies that determine the ways of implementing information processes.

Information environment is a collection of systematized and specially organized data and knowledge.

Information technology (IT) is a set of methods and software and hardware combined into a technological chain that ensures the collection, processing, storage, distribution and display of information in order to reduce the labor intensity of the processes of using information resources.

The term “information technology” has become widespread relatively recently in connection with the use of computer technology in performing operations with information.

Information technologies in economics and management are based on hardware and software. Hardware is one of the supporting technologies, i.e. can be used in any sphere of human activity. The software organizes the process of processing information in a computer and solving professional problems of users.

Areas of application of information technologies are systems for supporting human activities (managerial, commercial, industrial), consumer electronics and various services, for example, communications, entertainment.

There are several generations of IP.

First generation IC(1960-1970) was built on the basis of central computers on the principle of “one enterprise - one processing center”, and the IBM operating system - MVX - served as the standard application execution environment.

Second generation IC(1970-1980) is characterized by partial decentralization of information systems, when mini-computers of the DEC VAX type, connected to a central computer, began to be used in offices and departments of the organization.

Third generation IC(1980-1990) is determined by the emergence of computer networks that unite disparate information systems into a single system.

Fourth generation IC(1990 - to the present time) is characterized by a hierarchical structure in which central processing and unified management of IS resources is combined with distributed information processing. As a central computing system a supercomputer can be used. In most cases, the most rational solution seems to be an IS model organized according to the principle: central system server - local servers - client stations.

1.3. Classification of information systems

Information systems can be classified according to a number of criteria: by purpose, by hardware structure, by mode of operation and by the nature of interaction with users.

1.3.1. Classification of information systems by purpose

According to their purpose, information systems can be divided into information management, information retrieval, decision support systems, data processing and information and reference systems.

Information and management systems - these are systems for collecting and processing information necessary for managing an organization, enterprise, or industry.

Decision support systems are designed to accumulate and analyze data necessary for making decisions in various areas of human activity.

Information retrieval systems- these are systems whose main purpose is to search for information contained in various databases, various computer systems, usually separated over considerable distances.

TOinformation and reference systems These include automated systems that operate interactively and provide users with reference information.

Data processing systems is a class of information systems whose main function is the processing and archiving of large volumes of data.

1.3.2. Classification of information systems by hardware structure

This classification of information systems divides them into single-processor, multiprocessor and multi-machine systems (located systems, remote access systems and computer networks).

Single-processor ICs are built on the basis of one computer processor, thenlike multiprocessor systems use the resources of several processors.

Multi-machine systems are computer complexes. IN concentrated In computing systems, the entire complex of equipment, including user terminals, is concentrated in one place, so communication between individual computers of the system does not require the use of a data transmission system.

Remote access systems(with teleprocessing) provide communication between user terminals and computing facilities by transmitting data over communication channels (using data transmission systems).

Computer networks is an interconnected set of geographically dispersed data processing systems, means and systems of communication and data transmission, providing users with remote access to computing resources and collective use of these resources.

1.3.3. Classification of information systems by operating mode

If we consider the operating mode of information systems used, we can distinguish single-program And multiprogram computer system modes.

IN single-program In the operating mode, only one program is located and executed in the computer memory. This mode is usually typical for microcomputers and personal computers, that is, for personal computers.

IN multiprogram(multi-program) operating mode, the computer memory contains several programs that are executed partially or completely between processor transitions from one task to another, depending on the situation in the system

Based on the nature of user service, there are batch modes, as well as individual and collective use modes.

Batch Processing is the processing of data or the execution of tasks accumulated in advance in such a way that the user cannot influence the processing while it is in progress. It can be carried out in both single-program and multi-program modes.

In mode personal use all system resources are placed at the disposal of one user, whereas in collective use simultaneous access of several independent users to computer system resources is possible. Collective use in the request-response mode assumes that the system serves each user's request without interruption.

1.3.4. Classification of information systems by the nature of interaction with users

Based on the nature of interaction with users, systems operating in dialog and interactive modes are distinguished.

IN interactive mode a person interacts with an information processing system, and the person and the system exchange information at a pace commensurate with the pace of human information processing.

Interactive mode - This is a mode of interaction between a person and the information processing process, expressed in various kinds of influences on this process, provided for by the control mechanism of a particular system and causing a response from the process.

According to the characteristics of the functioning of the information system over time, there are real time- an information processing mode in which the interaction of the information processing system with processes external to it is ensured at a pace commensurate with the speed of these processes.

1.3.5. Composition and quality characteristics of information systems

Elementary operations of the information process include:

collection, transformation of information, input into a computer;

transfer of information;

storage and processing of information;

providing information to the user.

There are two main groups of characteristics that need to be taken into account when analyzing the quality of information processes: time characteristics and characteristics of the quality of the resulting information at the output of the information process.

Indicators of temporary properties of information processes include:

the average time and dispersion of the execution time of the information process (the average response time of the information system to a user request);

the duration of the time interval during which the information process is completed with a given probability.

The quality of information systems is characterized by:

data reliability - the property of data not to contain hidden errors;

data integrity - the property of data to retain its information content;

data security - protection of data from unauthorized access to it.

So, we examined the basic terms and concepts of information technology, classified information systems, studied the structure of the information process, as well as the characteristics and quality indicators of information processes.

Lecture 2. Classification of personal computers

Hardware is the basis of information technology, so the choice of computer and peripheral equipment significantly influences the efficiency of information technology. Different types of professional activities often place completely different demands on computer equipment, and it is important for a specialist to be able to optimally select computer equipment.

We will not dwell on the structure of the basic set of a personal computer, consisting of a system unit, keyboard and mouse, since when studying the subject “Informatics” this material is studied in detail in the section on basic information about PCs.

There can be many reasons for using personal computers (PCs) in professional activities, and depending on the goals and tasks to be solved, a certain type of computer is selected to automate a specialist’s workplace.

If you are an accountant, you need to purchase a desktop PC to automate your time-consuming bookkeeping. For a manager whose work involves traveling, a laptop will be suitable for high-quality execution of contracts and easier work with the client database. The desire to automate the accounting of goods flows will lead a businessman to the idea of ​​purchasing a mobile pocket computer (tablet or smartphone). And for inventory of large warehouses, a wearable (wearable) computer, which is not yet very familiar to us, is suitable - something between a wristwatch and a smartphone.

All computers can be divided into several categories:

basic desktops- universal desktop PCs;

mobile computers - tablet PCs, laptops, smartphones, wearable computers;

specialized PC- network computers, workstations and high-level servers;

supercomputer systems.

2.1. Universal Desktops

There is no need to explain to anyone what a desktop computer is - it is a device for beautifully formatting any texts, forms and contracts; maintain accounting records; manage the organization’s finances and work with the client database, as well as perform various calculations, draw, listen to music and watch movies, exchange messages on social networks or by e-mail, or “walk” on the World Wide Web.

A typical desktop personal computer consists of a system unit, monitor, keyboard and mouse (minimal configuration).

The most important part of a computer is system unit containing CPU And RAM(RAM) - the heart and brain of the PC, hard disk(HDD - hard disk drive), drives for reading and writing information from optical disks(CD, DVD or Blu-ray Disk) and several so-called ports (COM, LPT, USB) - boards equipped with connectors for connecting additional devices to the computer: for printing - a printer, for communication with other computers and access to the Internet - modem , for entering images into a computer - scanner and some other devices.

The architecture of modern computers was proposed by the company IBM and is still used today with some modifications. At first it was IBM RS-XT, Then IBM RS-AT compatible computers. Now computers based on processors are compatible with IBM in architecture Intel And AMD, which are produced not only in the USA, but also in Europe and Asia by manufacturing companies that have adopted the IBM standard. It is for these computers that the operating system is used Windows famous company Microsoft.

However, there is another standard - Apple, on the basis of which series computers are produced Mac Pro(desktop computers) and iMac(monoblocks). Computers in this group have their own “Apple” software, in particular their own operating system macOS X.

What is the fundamental difference between IBM and Apple? The first of them chose the tactics of open architecture (with the sale of patents). Any company, having acquired a patent, can start producing computers using IBM technology. Thus, it is possible to assemble a PC from independently manufactured parts. This is what ensured the widespread use of IBM computers.

Apple does not sell its patents, so its computers are more expensive and less common.

This is interesting

In 1984, Apple was the first in the world to create a Macintosh computer with a then unusual graphical interface and a mouse, which the entire computer world made fun of.

How wrong they were! Back then, no one knew that future PCs would increasingly look like Macs.

In practical activities, an important aspect of working with a computer is the storage of information by the user. For this purpose they are used optical discs(CD, DVD, BD), USB flash drives(flash drives), memory cards And external hard drives. All of the listed devices are classified as long-term memory devices.

Optical CDs can store information up to 700 MB. For recording, discs labeled CD-R (write once) and CD-RW (rewritable discs) are used.

Standard DVD allows you to store and read a larger amount of information. Physically, a DVD may have one or two working sides and one or two working layers on each side. The disk capacity depends on their number - up to 17 GB.

This is interesting

Do you know what the abbreviation DVD stands for? Well, of course, you know - digital video disc. This definition is firmly entrenched in the minds of most users. But initially these three letters stood for Digital Versatile Disc, i.e. digital versatile disk. Over time, the word Versatile was replaced by the more euphonious video, since this format was primarily a way to distribute video films.

On optical media Blu-ray Disc(or BD) you can save information up to 100 GB. BD discs, like DVDs, can also have several working layers.

This is interesting

In the name Blu-ray, the letter "e" was deliberately removed from the word "blue" in order to be able to register a trademark, since the expression "blue ray" is a commonly used expression and cannot be registered as a trademark.

Interface USB(USB, English Universal Serial Bus - “universal serial bus”) - a serial interface for connecting peripheral devices to computer technology. It has become very widespread and has actually become the main interface for connecting peripherals to household digital equipment.

The interface allows not only to exchange data, but also to provide power to the peripheral device.

Thanks to the USB interface, users have the opportunity to quickly and easily store fairly large amounts of information. For this, flash drives or flash drives are used. The capacity of modern flash drives reaches 128 GB!

2.2. Laptops

Anyone who needs a smart and mobile assistant for every day at work and at home will undoubtedly choose a portable PC (English notebook). Laptop is a full-fledged portable computer that contains typical PC components, including a monitor, keyboard and pointing device (usually a touchpad, or touchpad), and batteries. Laptops are small in size and weight; the battery life of laptops varies from 2 to 15 hours. Depending on the multimedia capabilities, gaming, multimedia and office laptops can be distinguished.

2.3. Pocket personal computers, communicators and smartphones

2.3.1. Pocket personal computers

An attempt to shrink a desktop computer to the size of a chocolate bar gave birth to a new class of computers - pocket personal computers(CPC). There is no exact date for the invention of the PDA, we can only say that the idea of ​​​​handheld computers finally took shape in the period of the 70s - 90s. During this time, a path has been passed from programmable calculators to color PDAs that allow you to watch videos and access the Internet. About 10 new operating systems and about a hundred different PDA devices were created. The original term was first applied on January 7, 1992 by John Sculley to the Apple Newton (Fig. 1).

Rice. 1. Apple Newton PDA

Rice. 2. Communicators

The main capabilities of the PDA include viewing maps of the area, making all kinds of records (memos, contact information, notes), making a schedule, making changes to the diary, reading books, communicating by e-mail or using instant messengers, listening to music and viewing photos and films , use a voice recorder, create text documents, presentations, spreadsheets, and of course play.

PDAs have been replaced by communicators and smartphones.

2.3.2. Communicators and smartphones

Communicator(PDA phone) - a pocket personal computer, supplemented with the functionality of a mobile phone (Fig. 2).

Smartphone(English smartphone - smart phone) - a mobile phone, supplemented with the functionality of a pocket personal computer (Fig. 3).

The difference between a smartphone and a communicator was noticeable at the dawn of the appearance of these devices. At that time, it was mandatory for a communicator to have either a touch screen or a qwerty keyboard; it was much larger in size than smartphones, and was controlled by systems specially designed for communicators. The smartphone often did not have a touchpad, it made do with a telephone keyboard, and the operating system, stripped down to the maximum, greatly limited its functionality.

IN lately The line between “regular” phones and smartphones is increasingly blurred; new phones (with the exception of the cheapest models) have long acquired functionality that was once unique to smartphones, for example, email and an HTML browser, as well as multitasking.

2.4. Wearable personal computers

A wearable computer is a computer that you can carry on your body (something between a wristwatch and a smartphone). At the moment there are no clear specifications and standards for this device.

A wearable computer makes it possible to work, communicate, and have fun using a computer all the time and at the same time have complete freedom of movement (Fig. 4).

CPD can enhance the capabilities of workers whose responsibilities include scanning, collecting and sorting information in large volumes, for example, warehouse workers during inventory. In conjunction with wearable computing, tiny, lightweight scanners and thermal imagers that are designed to be worn on the finger can be used (Figure 5).

Rice. 5. Application of R&D in production

One of the options for a wearable computer is the so-called “interactive glasses” (google glass). The device is a minicomputer with a webcam, scanner and Internet access (Fig. 6). The image in this case is projected onto the inside of the glasses. The entertainment capabilities of the augmented reality of such a device are quite wide: recognizing the faces of surrounding people and comparing them with photos of friends of an account on a social network; displaying the shortest route for motorists, etc.

Rice. 6. Augmented reality glasses Google Glass

2.5. Specialized PCs

Specialized computers are designed to solve a specific narrow range of tasks or implement a strictly defined group of functions. Such a narrow orientation of computers makes it possible to clearly specialize their structure, significantly reduce their complexity and cost while maintaining high performance and reliability of their operation.

Specialized computers are designed to solve a specific range of problems. Such computers include, for example, on-board computers of cars, ships, airplanes, and spacecraft.

Specialized computers that connect enterprise computers into one network are called file servers. Computers that ensure the transfer of information between various participants in the worldwide computer network are called network servers.

2.6. Supercomputers

Supercomputer - specialized computer, significantly superior in its technical parameters and computing speed to most existing computers in the world (Fig. 7 and 8).

A certain range of tasks turns out to be beyond the capabilities of personal computers and high-performance servers. Among the areas of application of supercomputers are atomic and nuclear physics, meteorology, seismology, and mathematical modeling.

Rice. 7. Supercomputer Sequoia ,
Livermore National Laboratory. Lawrence (USA, California),
memory capacity – more than 1600 TB

Rice. 8. Supercomputer “Lomonosov”,
Moscow State University named after M.V. Lomonosov
(Russia, Moscow), memory capacity – about 1800 TB

Lecture 3. Technical means of information technology

For effective professional work, it is important to have a good understanding of peripheral computer equipment and be able to choose what will best help you organize productive work. Let's study computer hardware in more detail.

3.1. Monitors

Computer monitor (display) is a device designed to display text and graphic information on a computer screen.

We perceive all visual information from the computer through the monitor. It doesn’t matter whether we are drafting documents, working with a specialized program such as accounting, sending email or viewing news from the Internet on the screen, we inevitably use a monitor.

Good monitor- this is also the health of the person behind him. Therefore, it would be unwise to skimp on a monitor when choosing a computer.

A little over 100 years ago, Carl Ferdinand Braun, looking for a new way to measure alternating current, assembled the first cathode ray tube with a three-inch round mica screen and a phosphor coating. Little did he imagine that his device would be the first modest step in technology that would radically change the way people perceive and use information. This invention has found application in many devices and, above all, in video terminals.

Further development has led to the production of increasingly larger screens with high image quality, while their cost is constantly decreasing. And if not so long ago a 17-inch color monitor was considered a luxury, today it, with improved basic parameters, has already become a standard, and there is a clear trend towards the use of screens with a diagonal of more than 20 inches.

Speaking about monitors (displays), we can divide them into two fundamentally different classes: cathode ray tube (CRT) monitors and flat-panel liquid crystal monitors (LCD).

3.1.1. CRT monitors

CRT monitors have high image quality, but their main disadvantage is large sizes, due to which they take up too much space on the table.

The image on the screen of a color monitor based on a cathode ray tube is formed using three electron guns that emit a stream of electrons. This flow, through a special metal mask (or grille), hits the inner surface of the glass screen, covered with triads of phosphor dots of primary colors - red, blue and green. The dots glow when they are hit by electrons from the corresponding guns, which are responsible for the glow of their light section of the dot.

The image is formed by scanning electron beams across the surface of the screen. The combination of dots glowing with different intensities creates all the richness of the color palette that we see on the screen (Fig. 9)

In the era of CRT monitors, the main parameter for choosing it was the scanning frequency, which affected the refresh rate of the image on the screen. At a scanning frequency of less than 85 Hz, the flickering of the image on the screen was very noticeable, which tired the users’ eyes and impaired vision. After some time, the convexity of the screen became another criterion, as cathode-ray monitors with a flat screen began to be produced, which distorted the image much less (Fig. 10).

Rice. 9. The principle of constructing an image on a CRT monitor

Rice. 10. CRT monitor

3.1.2. LCD monitors

LCD monitor is a flat display based on liquid crystals.

The first working liquid crystal display was created by Fergason in 1970. Previously, LCD devices consumed too much power, had a limited service life, and had poor image contrast.

Liquid crystals are organic substances that can change the amount of light transmitted under voltage. A liquid crystal monitor consists of two glass or plastic plates with a suspension between them. The crystals in this suspension are arranged parallel to each other, thereby allowing light to penetrate the panel. When an electric current is applied, the arrangement of the crystals changes and they begin to block the passage of light.

Rice. 11. The principle of constructing an image on an LCD monitor

Rice. 12. LCD monitor

Unlike cathode ray tubes, liquid crystal displays provide high-quality images without flicker and with significantly lower levels of radiation in the very low frequency range that is most dangerous to human health. They also have a completely flat screen and therefore lack much of the geometric distortion found in conventional monitors. In addition, they take up much less space and have significantly lower power consumption

3.2. Printers

Printer is an external computer peripheral device designed to output text or graphic information stored in the computer onto a hard physical medium, usually paper.

Despite the rapid development of the Internet, e-mail, direct data exchange and growing electronic document flow, the importance of paper documents is still great, and this situation is unlikely to change in the near future. Still, a document is usually understood as something tangible, and many computer users simply refuse to view a document on a monitor screen. Moreover, many errors are better visible on paper.

It is the printer that turns a virtual-mythical file before our eyes into a document with text, tables and graphs. It allows you to print images on paper for later use.

The first printers were only able to reproduce letters and characters, but a modern laser printer is capable of printing a magazine page with all color illustrations in excellent quality in a few seconds.

3.2.1. Dot matrix printers

The oldest printing method currently in use is impact matrix printing. Impact-type printers (matrix and linear matrix) still remain the only option where maximum reliability and long print life at a minimum cost are required.

For most users, dot matrix printers are associated with something obsolete. In modern offices, as a rule, laser printers are used.

The main complaints that users make about dot matrix printers are: low speed printing, noise during operation and not always high quality copies.

The principle of operation of a dot matrix printer is similar to a conventional typewriter: between the print head and the paper there is a ribbon soaked in ink, and the head itself is like a set of several, usually 9 or 24 needles, each of which, through a ribbon with ink, prints on the paper in a certain place point. Their combinations form letters, images, drawings and table frames (Fig. 13).

Rice. 13. Printing principle of a dot matrix printer

Since there are a lot of such dots to be applied, the printer makes noise during operation. The more needles, the smaller the dots and better quality printing, because the eye ceases to distinguish individual dots on paper; the slower the page will render.

The operating speed of dot matrix printers is low, and the print quality is very mediocre. Nevertheless, dot matrix printers continue to enjoy continued success.

Printers with an impact operating principle have one unique advantage - it is impossible to make corrections to a document unnoticed, because each needle of the print head “drives” its portion of ink into the paper, slightly pushing it through and forcing the ink to penetrate deeply between the fibers of the paper (Fig. 14 ). For most documents made on an inkjet printer, some of the text can be carefully washed away, while letters produced on a laser printer can be removed quite easily and almost completely by scraping.

Documents printed on dot matrix printers automatically receive an additional degree of protection against unauthorized modification. Because of this, many banks use impact matrix printers exclusively (Fig. 15).

Figure 14. Quality of the resulting image
(matrix printer)

Rice. 15Matrix printer

The next positive quality of dot matrix printers is the ability to print multilayer documents up to 4–5 carbon copies or on coated paper for self-copying. This is used, for example, when printing airline tickets, certificates, and some financial documents, the number of which is strictly taken into account.

3.2.2. Inkjet printers

When did they appear inkjet printers, the era of clear, bright pictures and high-quality fonts in Windows has begun.

The operating principle of inkjet printers is similar to dot matrix printers in that the image on the media is formed from dots. But instead of heads with needles, inkjet printers use a nozzle array (that is, a head) that prints with liquid ink. Ink is sprayed onto the paper under high pressure from small nozzles. As a result, a dot appears on the paper, 10-20 times smaller in size than the dot from a dot matrix printer. The pictures are clearer and more realistic. Disadvantages of inkjet printers: high price of consumables (ink cartridges); if water gets in, the image on the paper deteriorates. However, inkjet printers still won the hearts of users.

Rice. 16. Printing principle of inkjet printer

Rice. 17. Inkjet printer

3.2.3. Laser printers

The most important element of a laser printer is the rotating photodrum, which is used to transfer the image to paper (Fig. 18).

Rice. 18. Printing principle of laser printer

Rice. 19. Laser printer

The static charge is evenly distributed over the surface of the drum. The laser generates a thin beam of light that is reflected from a rotating mirror. This beam, hitting the photodrum, electrifies parts of the drum. Thus, a copy of the image appears on the photodrum. Then, using a developer drum, tonic (dye powder) is applied to the photodrum. Under the influence of a static charge, toner particles are attracted to the surface of the drum in electrified areas, forming an image. A sheet of paper is moved to the drum, then the sheet is given a static charge, opposite in sign to the points on the drum. When the paper touches the drum, toner particles are transferred (attracted) to the paper. Then the sheet is passed between two rollers, heating it to 180...200 ºС. After the printing process, the drum is completely discharged, cleaned of adhering toner particles and is ready for a new printing cycle. The described process occurs quite quickly and provides fairly high quality.

The laser printer (Fig. 19) has virtually no disadvantages. These include only expensive color printing, so inkjet printers are more often used to print color images

Advantages of laser printers: fast and silent printing, high typographic print quality.

3.2.4. Plotters

To display complex and wide format images special output devices are used - plotters (Fig. 20).

Rice. 20. Plotters

3.3. Scanners

A scanner is a device designed to convert graphic information of various types into computer form.

To enter a document into a computer without a scanner, you can type its text from the keyboard. A simple drawing can probably be repeated in a graphics editor. With color photography everything is much more complicated. However, by adding a scanning device to your computer that allows you to input images from paper or film into your PC, you can handle any of these tasks in a matter of minutes.

Of all the computer peripherals, scanners are undoubtedly among the most useful. And although scanners are inferior to digital cameras in speed and ease of use, they are more versatile, significantly cheaper and also provide much higher image quality.

Paired with a printer, the scanner performs the functions of a copier (remember how rarely you have to make copies of documents), and together with a modem it can replace a fax machine. Tablet devices can also scan bulky objects, such as coins or small objects.

There are several types of scanners, each corresponding to a different application: handheld, sheet-fed, flatbed and slide scanners.

The most common are flatbed scanners (Fig. 21), which provide high resolution. They resemble copiers: the material to be scanned is placed on a horizontal glass surface covered with a lid.

Sheet-fed (portable-page) devices (Fig. 22) scan individual pages. They are smaller in size and often have a cylindrical body. The page or photograph to be scanned is inserted into the scanner and ejected through the exit slot. Sheet-fed scanners are slower and often cannot scan thick originals. The main advantage of such scanners is their compactness, so you will always find where to place such a device.

Hand-held scanners (Fig. 23) are inconvenient to use, because they do not have a movement mechanism and a “steady hand” is required when working with them. A type of hand-held scanner is a barcode scanner.

Slide scanners allow you to recognize an image on film, negative or slide.

Rice. 21. Flatbed scanner

Rice. 22. Sheet-fed scanner

Rice. 23. Hand scanner

3 .4. Multifunctional peripherals

MFP devices (or MFPs) are made according to the “all-in-one” principle: they combine a fax, a scanner, a copy machine and a laser printer. Combined devices are rapidly becoming cheaper while their quality is increasing, so today such solutions seem quite reasonable. The most popular option is a combination of printer - copier - scanner.

Lecture 4. Information technology software. Basic software

Modern computer There is no way to do without programs. After all, it is the programs that determine the capabilities of the computer: what it will do - help balance the balance sheet or allow you to find information on the World Wide Web. Most programs would be more correctly called software products, because often their creation requires no less cost than the production of the computer itself. Almost any program, unless specifically stated, is commercial product, which is sold on par with computers.

Under software(software) information systems is understood as a set of software and documentary tools for creating and operating data processing systems using computer technology. In the very in general terms The software of the day of computing can be divided into basic (system) and application.

Basic (system) software organizes the process of information processing in a computer and ensures a normal working environment for application programs. Core software is so closely related to the hardware that it is sometimes considered part of the computer.

Application software directly aimed at solving the user’s professional problems.

The basic software includes:

operating systems;

service programs (utilities);

maintenance programs (test programs, control programs);

instrumental software (programming language translators, compilers, interpreters).

4.1. operating system

operating system(OS) is a set of special software designed to control the boot of a computer, the launch and execution of other user programs, as well as for planning and managing the computing resources of a personal computer. It provides control of information processing and interaction between hardware and the user.

One of the most important functions of the OS is the automation of information input-output processes, control of execution applied problems, decided by the user. The OS loads the desired program into the PC memory and monitors the progress of its execution; Analyzes situations that interfere with normal calculations and gives instructions on what needs to be done if difficulties arise.

Operating systems of personal computers are divided into single-tasking and multi-tasking.

IN single-tasking OS the user works with one specific program (task) at one point in time. Examples of such operating systems are the MS-DOS and MSX operating systems.

Multitasking OS allow you to work with several programs in parallel, and the number of programs depends on the power of the system. Examples include operating systems of all versions of Microsoft Windows, UNIX, OS/2, Linux, Mac OS.

Network OS are associated with the emergence of local and global networks and are designed to provide access to all resources of a computer network. Examples of such systems are Novell Net Ware, Microsoft Windows-NT, UNIX, IBM LAN.

4.2. Service software

Utylita- an auxiliary computer program as part of general software for performing specialized standard tasks related to the operation of equipment and the OS.

Utilities provide access to features (parameters, settings, settings) that are not available without their use, or make the process of changing some parameters easier (automate it) and expand the capabilities of operating systems.

Utilities can be included in operating systems, bundled with specialized equipment, or distributed separately.

Based on functionality, service tools can be divided into tools that improve the user interface, protect data from destruction and unauthorized access, restore data, speed up data exchange, archiving programs and antivirus agents.

Utility programs include viewer programs that allow you to view files of one or more formats. such as images, graphics, or listening to audio files. To view HTML, use utility programs - browsers.

Anti-virus protection software provides diagnostics (detection) and treatment (neutralization) of viruses. The term “virus” refers to a program that can multiply, infiltrate other programs, and perform various unwanted actions. The most common Russian antivirus programs are DRWeb and Kaspersky.

Archiver- a computer program that compresses data into one archive file for easier transfer or compact storage. The data is usually files and folders. The process of creating an archive is called archiving or packaging (compression, compression), and the reverse process is called unpacking or extraction. Examples of archivers include WinZip and WinRAR.

4.3. Maintenance programs

Under maintenance programs refers to a set of software and hardware tools for diagnosing and detecting errors during the operation of a computer or computer system as a whole.

They include tools for diagnostics and test monitoring of the correct operation of the PC and its individual parts, as well as special programs for diagnosing and monitoring the computing environment of the information system as a whole, including software and hardware control that automatically checks the functionality of the system.

As an example test program You can cite the Doctor Hardware program, the CheckI t package for Windows.

When you use your computer intensively, there is a need to service the hard drive.

Hard drive maintenance means:

procedure for checking the integrity of the disk partition table (partition),

boot sector (boot record),

file location tables (FAT),

directory structure and files,

search for violations and their correction.

To find and solve problems, hard drive maintenance programs are used; and if corrections are not possible, use a disk formatting program.

4.4 Tool software

Programming system- this is a set of tools that include an input programming language, a translator, machine language, libraries of standard programs, tools for debugging translated programs and composing them into a single whole.

Translator programming languages ​​is a program that translates program text from a programming language into machine code. In programming systems, a translator translates a program written in the input programming language into the machine command language of a specific computer. Depending on the method of translation from the input programming language, translators are divided into compilers and interpreters.

IN compilation the processes of translation and program execution are separated in time. First, the compiled program is converted into a set of machine language object modules, which are then assembled (linked) into a single machine program, ready to be executed and stored as a file.

Interpreter carries out step-by-step translation and immediate execution of the statements of the source program, with each statement of the input programming language translated into one or more machine language commands.

A special place in the programming system is occupied by assemblers, which are a complex consisting of an input assembly language programming language and an assembler-compiler.

An assembler is a mnemonic (conditional) recording of machine instructions and allows you to obtain highly efficient programs in machine language.

Examples of programming systems include Delphi, Java, C#, PHP, Pascal ABC,Basic.

Lecture 5. Application software

Application software designed to develop and perform specific user tasks (applications).

Application software runs under the control of underlying software, in particular operating systems. They are powerful tool automation of tasks solved by the user, almost completely freeing him from the need to know how the computer performs certain functions and procedures for processing information.

Application software includes application packages for various purposes and user work programs.

Application package(PPP) is a set of programs designed to solve problems of a certain class.

The following types of application software are distinguished:

general purpose;

method-oriented software;

problem-oriented software;

Software for global networks;

Software for organizing (administrating) the computing process.

5.1. General purpose application software

General-purpose application software is universal software products designed to automate the development and operation of user functional tasks and information systems in general.

This class of PPP includes:

text editors and processors;

desktop publishing systems;

graphic editors;

spreadsheets;

database management systems (DBMS);

integrated packages;

Case technologies;

shells of expert systems and artificial intelligence systems.

Editor called PPP, designed for creating and modifying texts, documents, graphic data and illustrations. According to their functionality, editors can be divided into text and graphic editors, word processors and publishing systems.

5.1.1. Word processing programs

Text editors are used to process text information and perform mainly the following functions: writing text to a file; insertion, deletion, replacement of characters, lines and text fragments; spell checking; text design in different fonts; searching and replacing words and expressions; text printing. Word processors do not work with illustrations, tables, and other embedded objects.

The most widely used text editors are Notepad (standard Windows program), Notepad++, Geany, UltraEdit.

Word processors– these are application programs designed for creating text documents that can, in addition to monolithic text, also contain list structures, tables, formulas, business and illustration graphics.

The presence of developed functions for the layout of complex text documents allows the use of word processors as short-run desktop publishing systems.

Modern word processors allow you to create and cleanly electronic documents for paperless office work (automated office), as well as for publication on the Internet in web page format.

Most common free(free software) word processors: WordPad (included in MS Windows), OpenOffice Writer, Google Docs (online only), LibreOffice Writer, Calligra Suite Words.

Most common paid(proprietary or proprietary software) word processors: Microsoft Word, WordPerfect (developed by Corel Corporation), iWork (developed by Apple).

Publishing systems combine the capabilities of text and graphic editors and have advanced capabilities for creating strips of graphic materials and subsequent printing. These systems are focused on use in publishing and are called layout systems.

Examples of such systems are Microsoft Publisher, Adobe InDesign, Adobe PageMaker, Adobe FrameMaker, Apple Pages, QuarkXPress. Free ones include Scribus and PagePlus Starter Edition.

5.1.2. Graphic editors

Graphic editors designed for creating and processing graphic documents, including diagrams, illustrations, drawings, tables.

The most famous graphic editors are:

free: Microsoft Paint (included in MS Windows OS), Paint.NET, Blender, GIMP, Inkspace;

proprietary: Adobe Photoshop, CorelDRAW, Adobe Illustrator, ACDSee, Autodesk Maya, Autodesk 3ds Max.

5.1.3. Spreadsheets

Spreadsheet is a program for processing numerical data in tables (or two-dimensional arrays). Some programs organize data into “sheets,” thus offering a third dimension.

Data in a table is stored in cells located at the intersection of columns and rows. Cells can store numbers, character data, and formulas. Formulas specify the dependence of the values ​​of some cells on the contents of other cells.

Spreadsheets (ET) are a convenient tool for automating calculations. Many calculations, particularly in the field of accounting, are carried out in tabular form: balance sheets, pay slips, cost estimates, etc. In addition, it is convenient to solve a number of mathematical problems using numerical methods in tabular form. Usage mathematical formulas in spreadsheets allows you to represent the relationship between various parameters of some real system.

The most popular spreadsheets include MS Excel and iWork Numbers (both paid), as well as OpenOffice Calc and LibreOffice Calc (free).

5.1.4. Database Management Systems

To work with databases, special software is used - database management systems (DBMS)).

Database (DB) is a collection of specially organized data sets stored on disk. Database management includes data entry, data correction and data manipulation, i.e. adding, deleting, retrieving, updating and other operations.

Depending on the method of organizing data, there are network, hierarchical and relational DBMSs. Of the available DBMSs, the most widely used are Microsoft Access, Paradox, FoxPro, Oracle, MS SQL Server, MySQL.

5.1.5. Integrated Packages

Integrated packages is called software that combines various software components of general-purpose application programs. Typically they include a text editor, a spreadsheet, a graphics editor, a database management system, several other programs, and a communications module.

The most common of the available integrated packages are:

free software: Apache OpenOffice, LibreOffice, Calligra Suite;

proprietary software: MS Office, Corel WordPerfect Office, iWork (Apple office suite).

5.1.6. CASE technologies

CASE technology used when creating complex information systems, usually requiring collective implementation of a project in which various specialists participate: system analysts, designers and programmers.

CASE technology allows you to separate the design of an information system from programming and debugging itself, while system developers are engaged in design at a higher level, without being distracted by details.

Often, the use of CASE technology goes beyond the design and development of information systems. This makes it possible to optimize the models of organizational and management structures of companies and allows them to better solve problems such as planning, financing, and training.

Modern CASE technologies are successfully used to create information systems of various classes - for banks, financial corporations, and large firms. Among the CASE technologies available on the market, the following software products can be distinguished: AllFusion ERwin Data Modeler (formerly ERwin), BPwin, OO win, Composer.

5.1.7. Expert systems

Expert systems- these are knowledge processing systems in a highly specialized field of preparing user solutions at the level of professional experts.

Expert systems are used to forecast situations, diagnose the state of the company, target planning, and manage the functioning process. They arose as a result of the computerization of processes for solving problems such as “what will happen if ...”, based on the logic and experience of specialists. The main idea here is to move from strictly formalized algorithms that prescribe how to solve a problem to logic programming indicating what needs to be solved on the basis of knowledge accumulated by subject matter experts.

Examples of expert system shells used in economics include Expert-Ease.

5.2. Method-oriented application software

Method-oriented application software is distinguished by the fact that its algorithmic basis implements some economic and mathematical method for solving a problem.

Method-oriented packages are widely used in the processing of experimental data. Typically, the processing of experimental data consists of establishing some dependence. This task is quite general and finds application in a wide variety of research areas.

Method-oriented software includes PPP

mathematical programming (linear, dynamic, statistical);

network planning and management. For example, the PlanWIZARD program automates management activities in construction organizations - scheduling, planning projects in construction, obtaining preliminary cost estimates of the project, constructing schedules that make it possible to visualize the timing and importance of the work being performed;

queuing theories used to study service processes in transport, trade, medicine, etc.;

mathematical statistics.

Examples of such programs are Microsoft Project, Sure Trak, Open Plan Professional.

5.3 Problem-oriented application software

Problem-oriented application software- These are software products designed to solve a problem in a specific functional area.

From the whole variety of problem-oriented software, we can distinguish groups designed for complex automation of control functions in industrial and non-industrial spheres, as well as software for subject areas.

5.3.1. Problem-oriented application software for the industrial sector

Comprehensive software for integrated general purpose applications for the industrial sector is divided into the following groups:

Software for automating all activities of a large or medium-sized enterprise. Of the Russian programs of this class, the Galaktika system should be noted;

software packages for production management of a certain type;

specialized software products such as MMPS, MES, which make production more flexible and speed up its adaptation to market conditions;

Software for managing the entire process chain, ensuring production of products, starting from the design of product parts and ending with the receipt of the finished product.

The cost of most complex problem-oriented software is high, sometimes over a million dollars, but large companies incur such costs to automate their activities.

5.3.2. Problem-oriented application software for non-industrial areas

It is intended to automate the activities of companies not related to material production (banks, stock exchange, trade). The requirements for software of this class largely coincide with the requirements for industrial software - the creation of integrated multi-level systems.

The world leaders in the creation of software of this class are the main computer manufacturing companies, as well as companies that produce exclusively software (Oracle, Informix).

From all the abundance of complex packages of application programs in the non-industrial sphere, we will single out packages that automate the financial and legal spheres.

Accounting software (accounting software)

Russian enterprises use accounting systems of four generations.

First generation BU software characterized by functional limitations and difficulty adapting to rapidly changing accounting rules and was intended for operation in the form of an automated workstation (AWS) on standalone computers(“Finance without problems”, “Sail”, “Turbo-accountant”, “Balance in 5 minutes”).

Second generation BU software differs in greater functional completeness and adaptability to various changes in accounting rules. Among them, PPPs intended for operation in local networks or autonomously appeared for the first time.

Such software includes the following software systems: “1C: Accounting”, “Info-Accountant”, “Questor”, “Best”, “Monolith-Info”, etc.

Modern third generation BU software integrates into complex automation systems for enterprise activities. Most of these packages run under operating system control Windows systems and is intended for use in local networks. New accounting software programs, as a rule, have built-in development tools and are fully compatible with other software, ensuring further expansion and development of the system.

An example of such third-generation software is the BU Office software, which combines products from 1C and Microsoft and allows not only to automate the functions of an accountant, but also to organize all of the company’s office work in the form of an “electronic office.”

The fourth generation is accounting systems, and in their essence they are already complex corporate information systems (CIS), which are characterized by integrated technological solutions.

Financial management software (FM software)

They appeared in connection with the need for financial planning and analysis of the activities of companies. Today's Russian market for PPP FM is represented mainly by two classes of programs: for financial analysis of an enterprise and for assessing the effectiveness of investments.

Enterprise financial analysis programs focused on a comprehensive assessment of past and current activities. They allow you to obtain an assessment of your overall financial condition, including assessments of financial stability, liquidity, efficiency of capital use, and property valuation.

The source of information for solving this type of problem is accounting documents, which are compiled in uniform forms regardless of the type of property and include the actual balance sheet of the enterprise, a report on financial results and their use, a report on the condition of property, a report on the availability and flow of funds.

Among the software of this class one can highlight EDIP (Centrinvest Soft), AltFinance (Alt), and Financial Analysis (Infosoft).

Investment performance assessment programs focused on assessing the effectiveness of capital investments and real investments. The most famous in this class of software are: Project Expert (PRO-Invest Consulting); Al-Invest (Alt); FOCCAL (Centrinvest Soft).

For analysts of banks and investment funds, it is important to make decisions about the prospects of investments, and for financial managers of companies, a tool for detailed analysis of the previous and future activities of enterprises is important to make decisions on the implementation of a specific investment project.

For these purposes, the Investor software (InEk) was developed.

Legal reference systems software (SPS software)

SPS software is effective tool working with a huge amount of legislative information arriving in a continuous stream.

There are more than a dozen legal systems in Russia. The most famous and popular legal reference systems are “Consultant Plus”, “Garant”, “Kodeks” and “Referent”.

5.4. Wide Area Network Application Software

The main purpose of global computer network software is to provide convenient, reliable user access to geographically distributed network resources, databases, and message transmission. To organize e-mail, teleconferences, electronic bulletin boards, and ensure the secrecy of transmitted information in various global networks, standard (in these networks) application software packages are used.

An example is software for global network Internet:

access and navigation tools (browsers) - Microsoft Internet Explorer, Google Chrome, FireFox, Opera, Yandex.Browser;

mailers for electronic mail (e-mail). The most common currently are MS Outlook Express, The Bat!, Mozilla Thunderbird, Opera Mail.

In banking, standard application software packages have become widespread, ensuring the preparation and transmission of data in international networks SWIFT (Society for Worldwide Interbank Financial Telecommunications), Sprint Corporation, Reuters.

5.5. Software for organizing (administrating) the computing process

For these purposes in local and global computer networks More than 50% of the world's systems use software from Bay Networks (USA), which controls data administration, switches, hubs, routers, and message traffic.

So, we briefly got acquainted with the basic and application software that ensures both the operation of the computer itself and the activities of a specialist - a computer user in his professional field.

In practice, sometimes there are original problems that cannot be solved with existing application programs. In this case, the results are obtained in a form that is not satisfactory to the end user. Then, using programming systems or algorithmic languages, original programs are developed that take into account the requirements and conditions for solving specific problems of the organization.

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TOPIC: Information technologies in professional activities

1) Automation of user work in the MSOffice 2000 environment. User work environment and its settings

2) Database security and integrity

3) Creating queries to update, add, delete, create a table

4) Literature

1) Automation of user work in the environment MS Office 2000 .

User environment and settings

Any enterprise faces the problem of automating the work of individual employees and departments as a whole. The first problem with this is how to choose suitable software products? The desirable properties of an information system strongly depend on the size of the enterprise and the specifics of its business, but there are also universal requirements.

Of course, any enterprise needs tools for working with texts (creating, editing, document design), as well as for data processing (spreadsheets, DBMS analysis and planning tools). But this is usually not enough. After all, different people work with documents, and documents often consist of various parts, including texts, numbers, tables, graphs, diagrams, drawings, even sound or video.

Today, all this is possible thanks to the family of programs created by Microsoft to support office activities, Microsoft Office.

The Microsoft Office software suite includes several applications that form a single environment for processing a wide variety of information. Microsoft Office includes a powerful word processor

Microsoft Word, Microsoft Excel spreadsheets, Microsoft PowerPoint presentation tool, and work organization and planning tool Microsoft Outlook. In addition, there is professional version Microsoft Office, which in addition to the listed applications includes the Microsoft Access database management system (DBMS).

Application Interoperability

Microsoft Office features tight application integration.

This means that all programs included in Microsoft Office “know how” to exchange information and allow you to do this quite simply. For example, if you need to prepare a report on the results of a financial period containing illustrations, then the data can be processed in Microsoft Excel, graphs and charts can be built based on them, and then placed in the text of a document created in Microsoft Word. Moving the diagram is done using the operations of copying to the Microsoft Windows clipboard and pasting into a document, which are available through the main application menu, through toolbars, through hotkeys or through the context menu that appears when you click the right mouse button.

Finally, an illustration, like any other object, can be “linked” to a document by simply “grabbing” it with the mouse in one application and “dragging” it to a suitable location in another (“Drag and Drop” mode).

Microsoft Office applications allow the exchange of any data between any applications. For example, you can use charts from Microsoft Excel to design reports in Microsoft Word or to illustrate a presentation in Microsoft Power Point. You can place a piece of a table from Excel into the text of a Word document or into PowerPoint slide, or you can import it into the database Microsoft data Access. In addition, any Microsoft Office application allows you to place a drawing in any format, as well as a video clip or just an audio clip, into a document (be it text, spreadsheet, presentation or database).

When moving individual objects from one application to another, in addition to the usual copy/paste operation, it is possible to use a mechanism for linking the original object and its copy. In this case, when the source data in the Excel table changes, the chart built on its basis changes, and along with it the copy of the chart contained in the Microsoft Word document. This makes it possible efficient work with composite documents that use different sources.

For example, the data can be taken from an Access database. They will be updated automatically and anyone who wants to view such a document will see the most recent figures.

The Microsoft Office family contains a set of tools that are common to all applications. These include spelling and grammar checkers, a drawing tool, a tool for creating colorful titles, an organization chart editor, a tool for editing mathematical formulas, a photo editor, a picture library, etc. This also includes toolbars and even menus , which are standard elements of any Microsoft Office application. These tools are installed once on disk and then used by all Microsoft Office applications. This feature saves disk space, provides high-speed applications and a unified interface. You can easily get started with any Microsoft Office application by learning just one.

Starting with version 97, Microsoft Office includes a new application

Microsoft Outlook. This application is a tool for organizing and planning personal activities. Microsoft Outlook includes email, contact database, calendar, etc. But most importantly, it connects all applications, acting as a means of organizing work. WITH using Microsoft In Outlook, you can schedule an appointment by adding an accompanying document to the appointment description. This could be a list of issues that are planned to be discussed, in Microsoft format Word, or annual sales report in Microsoft Excel format. You can send the completed document by email or fax.

User environment and its configuration

Basic Concepts

The user's work with software products should be as comfortable as possible and carried out in an appropriate software and hardware environment (type of processor, amount of RAM and external memory, network and local operating system platform, etc.).

For the user's work, the user interface is of great importance (the appearance, size and location of the main screen, processing functions available through the menu system, toolbars, etc.). As a rule, the interface of application software products is built according to the type of graphical interface oriented to the Windows (or Macintosh) environment with developed controls: command buttons, drop-down menus, switches, etc.

Software products must guarantee reliable and safe operation for both the computer and the user’s information system (safety of computer devices, software, stored data). To a large extent, this is achieved by the presence in the software product of context-sensitive help and training systems, demo versions that reveal the functionality and technology of the software product, special software solutions to ensure the safety of programs and data, anti-virus protection, etc.

Application software products automate the activities of specialists (economists, managers, accountants, agents, etc.) in subject areas. A trend has emerged towards the creation of automated workstations - workstations that fully support all professional activities of the end user in a computer environment.

Many workstations, along with the main data processing functions, also include auxiliary functions, the so-called service. The service provides database maintenance functions - copying, restoring, archiving, exporting/importing data; performing work related to professional activities, such as preparing correspondence using a text editor, organizing calculations using a spreadsheet, using e-mail to send correspondence, etc.

The workstation also includes tools for configuring the software and hardware complex, which reconfigure the workstation taking into account technical characteristics computer technology, the composition of basic and auxiliary processing functions. Modern software products include a special software module or commands as part of the main menu to configure the environment and optimize the operation of software products.

When installing a software product - installation - global configuration is done, which means:

specifying a location for placing the software product on a magnetic disk;

choice functionality (software components, modules) for installation on a computer;

setting up the database structure (file composition, record structure);

setting up the operating and technical environment for the functioning of the software product.

Such configuration is usually performed by a qualified programmer, and changing the installation conditions will require reinstallation of the software product.

To improve end-user efficiency, online configuration tools are provided, including:

changing the access password to the software product;

activation/deactivation of processing functions (changing main menu functions);

Parametric configuration of menu commands;

Setting up screen forms;

Setting up output print forms;

Setting database formats (length and type of fields);

Determining where the database is stored on a magnetic disk;

Changing print settings (printer type, print page settings), etc.

The capabilities of the environment customization tools determine the flexibility of the software product. The trend in the development of application software products is also to create end-user tools. Tools of this type are designed to improve processing functions and create new applications by the end user.

Thus, for accounting packages, a set of tools of the following type is offered:

A screen form generator that allows you to create new and change existing screen forms (location on the screen of details corresponding to database fields, use of hint text, launch of processing procedures, color design, etc.);

Query language as a means of searching and filtering database records, selecting machine documents, and performing calculations on database data;

Macro programming keyboard and language macro commands (macros) designed to automate routine processing operations;

A report generator that provides output of requested information, generation of results at various levels, etc.

A trend towards mass use has emerged end users integrated packages focused primarily on the capabilities of standard software tools (text editor, spreadsheet, database). Integrated packages include a powerful arsenal of tools (macro programming, programming languages, add-ons, etc.) designed for the creation of application software products by both end users and professional programmers. Thus, the environment of the integrated package is, in a certain sense, an automated workplace that provides the end user with powerful and flexible tools.

The Microsoft Office software can rightfully be considered integrated, as it is characterized by:

Standardization of the implementation of basic processing operations (commonality of main menu items, techniques and technologies for performing the operations of creating, saving, printing, searching for documents and files);

Unity of principles for configuring and setting up programs;

Converting stored data formats;

Replacing the main menu with the application menu of objects when editing them.

2) Database security and integrity

The widespread introduction of information technologies into the life of modern society has led to the emergence of a number of general information security problems:

It is necessary to guarantee the continuity and correct functioning of critical information systems (IS) that ensure the safety of people and the environment;

It is necessary to ensure the protection of property rights of citizens, enterprises and the state in accordance with the requirements of civil, administrative and economic law (including the protection of secrets and intellectual property);

It is necessary to protect civil rights and freedoms guaranteed by current legislation (including the right to access information).

Security requirements in different information systems may differ significantly, but they are always aimed at achieving three main properties:

Integrity – information on the basis of which decisions are made must be reliable and accurate, protected from possible unintentional and malicious distortions;

Availability (readiness) – information and related automated services must be available, ready to work whenever they are needed;

Confidentiality – classified information should be accessible only to those for whom it is intended.

To solve information security problems, a combination of legislative, organizational, technological and standardization measures is necessary.

The main attention in the theory and practice of ensuring the security of the use of information technologies and systems is focused on protection from malicious destruction, distortion and theft of software and database information. For this purpose, problem-oriented methods and means of protection have been developed and developed:

From unauthorized access;

From various types of viruses;

From information leakage through electromagnetic radiation channels

etc. This implies the presence of persons interested in access to programs and data for the purpose of their unauthorized use, theft, distortion or destruction.

Let's consider modern methods of identifying and preventing unintentional threats to the security of the functioning of software (PS) and databases (DB), reducing the corresponding risks to an acceptable level and determining the actual achieved degree of security in the use of IS. In this regard, we will talk about algorithmic and software-technological security, using for brevity the terms “technological security” or simply “security”. The main unintentional threat will be the presence of internal defects in the software and database caused by design and implementation errors.

Factors determining the technological security of complex information systems:

Indicators characterizing the technological security of information systems;

Requirements for the architecture of the PS and DB to ensure IS security;

Resources necessary to ensure technological security of the IP;

Internal and external destabilizing factors affecting the safety of the functioning of software and databases;

Methods and means of preventing and reducing the impact of IP security threats from program and data defects;

Operational methods and means of increasing the technological safety of the functioning of the PS and DB by introducing temporary, program and information redundancy into the IS;

Methods and means of determining the real technological safety of the functioning of critical information systems.

The use of databases is characterized by the following properties:

1. EFFICIENCY: computer technology allows for quick access to information;

2. FULL ACCESSIBILITY: all information contained in the database is available for use;

3. FLEXIBILITY: it is possible to easily change the composition and form of issuing data that interests the user, changes to the database are also made quite simply;

4. INTEGRITY (of data): duplication of data is minimized, the possibility of ordering and consistency of data is provided, as well as work on updating it.

A number of interdependent concepts are also associated with the general characteristics of the database:

Database integrity is a state of a database in which all data values ​​correctly reflect the subject area (within specified restrictions on accuracy and consistency over time) and are subject to the rules of mutual consistency. Maintaining database integrity involves checking it and restoring or correcting it from any incorrect state that may be discovered. This is the responsibility of the database administrator, who uses the tools of the database management system. We can talk about file integrity in a similar way, although in typical cases files are subject to less extensive integrity checks.

Database security - Availability and characteristics of means (hardware, software, organizational, technological, legal, etc.) that ensure prevention or exclusion of:

Access to information by persons who have not received appropriate permission.

Intentional or unintentional destruction or alteration of data.

Database security is a property of a database, which means that the data contained in it will not cause harm to the user if used correctly to solve any functional problems of the system for which it was created. Often the concepts of “security” and “protection” of a database are considered synonymous.

Database efficiency -

The degree to which the results of using a database correspond to the costs of its creation and maintenance in working condition; if this indicator is assessed in monetary terms, it is called the economic efficiency of the database;

A general indicator of the quality of the state and use of a database based on a set of characteristics (including speed, availability, flexibility, integrity, security, safety, etc.) - technical efficiency of the database. The effectiveness of databases is usually assessed in relation to the conditions of their use in specific automated systems.

The most common security threats to databases are:

Unauthorized access to data via the Internet;

Stealing information with a query like SELECT *. It is very difficult to provide protection against threats of this type, since they are produced mainly by analysts who interact with the database core and have privileges for all kinds of data samples from all database tables;

Backup for the purpose of database theft.

The following elements must be included in a typical database protection model: organizational measures to ensure access to the server (preferably only locally); restrictions on access to the corporate network; protection of access to the DBMS; restrictions on the use of application software by a specific user.

To solve the problems discussed, you can use the most common methods of protecting the database: password protection, tools built into the DBMS for protecting information and monitoring user actions, identifying the user and checking his authority.

Each of these methods has its own advantages, but we must understand that it is impossible to ensure absolute data protection.

You can also use the most classic method of data protection - encrypt all database tables using a fairly strong crypto-algorithm. But this solution also has a number of disadvantages, for example, time loss during data encryption/decryption, the impossibility of indexing fields, the practical impossibility of complete recovery in case of system failures, etc.

Operational methods for increasing the security of database operation.

The inability to ensure its absolute security during the creation of a database, even in the absence of malicious influences, forces us to look for additional methods and means of increasing the safety of the database operation at the operational stage. For this purpose, methods for prompt detection of defects during execution are being developed and applied.

programs and data distortion by introducing temporary, information and program redundancy into them. These same types of redundancy are used to promptly restore corrupted programs and data and prevent the possibility of threats developing to a level that violates the security of the database.

To ensure high reliability and safety of the functioning of the database, computing resources are required to detect the manifestation of defects as quickly as possible, to accurately classify the type of existing and probable consequences of distortions, as well as for automated measures that ensure fast recovery normal functioning of the database.

Information redundancy consists in duplication of accumulated initial and intermediate data processed by programs. Redundancy is used to preserve the validity of the data that most impacts normal functioning DB and require significant time to restore. Such data usually characterizes some integral information about an external controlled process, and if it is destroyed, the process of managing external objects or processing their information may be interrupted, affecting the security of the database. Software redundancy is used to control and ensure the reliability of the most important management and information processing decisions. It consists in comparing the results of processing the same source data by different programs and eliminating the distortion of the results due to various anomalies. Software redundancy is also necessary for the implementation of automatic control and data recovery tools using information redundancy and for the functioning of security measures.

Along with a prompt response to distortions in the database, information about all manifestations of defects must be accumulated in order to use this data to localize the primary source of errors and correct the corresponding programs, data or hardware components. It is advisable to carry out the preparation, statistical processing and accumulation of data on the manifestations of distortions automatically with the issuance of summary data periodically or upon request for indication for specialists to prepare decisions on adjusting programs or restoring equipment.

Thus, the introduction of redundancy into programs and data helps to improve the quality of the database. Redundancy can have a particularly large impact on the reliability and security of solving problems in critical real-time systems. At the same time, it is possible to reduce debugging costs and partially ensure the necessary reliability and security of the database through means of increasing noise immunity, operational control and restoration of the functioning of programs and data. Means of operational protection of the computing process, programs and data, in turn, are complex systems and are not immune from errors that could lead to a violation of the security of the database. Therefore, a comprehensive analysis, allocation of resources and types of redundancy are required to maximize the safety of the use of critical databases.

3) Creating queries to update, add, delete, create a table

office automation security table query

Create an update request.

With an update request, you can add, change, or delete data in one or more records. You can think of update prompts as a more advanced version of the Find and Replace dialog box. You should enter a selection condition (roughly equivalent to a search pattern) and an update condition (roughly equivalent to a replacement pattern). Unlike the Find and Replace dialog box, an update query can accept multiple conditions and allows you to update a large number of records at once, as well as change records in multiple tables at once.

Please remember the following rules.

An update query cannot be used to add new records to a table, but it can change existing empty values ​​to specific values.

An update query cannot be used to delete entire records (rows) from a table, but it can change existing non-blank values ​​to null.

You can use update queries to change all the data in a recordset.

Additionally, you cannot perform an update request for following types fields in the table.

Fields whose record source is summary queries or cross-queries.

Fields with the “Counter” data type. Values ​​in fields with the Counter data type change only when a record is added to the table.

Fields in join requests.

Fields in unique value queries and unique record queries—queries that return non-repeating values ​​or records. This rule applies when you use an update query, or when you manually update data by entering values ​​into a form or table.

Primary keys involved in relationships between tables, unless those relationships have been configured to automatic execution cascade update through key fields and any related fields. A cascade update automatically updates any foreign key values ​​in the child table (the table on the "many" side of a one-to-many relationship) when the primary key value in the parent table (the table on the "one" side of the one-to-many relationship) changes.

Note. You cannot perform cascading updates on records that use a count field to create primary key values.

Adding records to a table using an append query.

An append query selects records from one or more data sources and copies them to an existing table.

Let's say, for example, that you need to get a database with a table of potential clients, and you already have a table with similar data. The data needs to be stored in one place, and you decide to copy it from the new database to an existing table. To avoid manually entering data, you can use an append prompt to copy records.

Benefits of Using an Add Request

Using a query to copy data, you can perform the following operations:

Adding multiple entries at once. When copying data manually, you typically have to copy and paste records multiple times. Using a query, you can select all the data you need at once and then copy it.

Preview data before copying it. You can view your selected data in Datasheet view and make any necessary changes before copying it. This is especially easy if the query contains criteria or expressions and you need several attempts to select the data correctly. An add request cannot be canceled. If an error is made, you will either have to restore the database using a backup or correct the error manually or using a delete request.

Refine your selection using conditions. For example, you might want to add records only for customers who live in a specific city.

Adding records when some fields in the data sources are missing from the target table. For example, suppose that the existing customer table has 11 fields, but the new table from which you want to copy data has only nine of them. You can use an append query to copy data from the nine matching fields, but you can leave the two non-matching fields blank.

Basic steps for creating an add request

Creating an add request involves the basic steps listed below.

Create a selection request. First you need to select the data you want to copy. If necessary, you can adjust the selection as many times as necessary.

Converting a select request to an append request. Once your selection is complete, change the add request type. Select target fields for each column in the add request. In some cases, Access selects target fields automatically. You can change the target fields or select them if this was not done automatically.

Preview and execute a query to add records. Before adding records, you can switch to Table View mode to preview the records being added.

Important. An add request cannot be canceled. Before running this, consider creating a backup copy of the database or target table.

Using queries to delete data.

A delete request is used when you want to delete entire records from the database, along with the key value that makes those records unique. It should be remembered that in the Access application, you can manually delete both entire records and individual parts of them in several ways.

There are two types of queries you can use to delete data from an Access database. The type of query used depends on what exactly needs to be removed.

If you need to delete individual fields in records of one or more tables, you should use an update query that replaces the existing values ​​with either empty value(that is, the absence of data), or an empty string (a pair of double quotes without a space between them).

The update query is used to delete individual fields because the default delete request only deletes entire rows. The process of using an update request to delete data consists of the following main steps: Create a select query and ensure that it returns only the data that needs to be removed; converting this request to an update request using NULL or empty strings as the new value; running this query to update existing data.

If you want to delete entire records (rows), you should use a delete query.

By default, a delete request deletes all data for each field in a record along with the value of the key that makes that record unique. When executing such a query, the entire table row is always deleted. The process consists of the following main steps: creating a select query and verifying that it returns only the data that needs to be removed; converting this request into a delete request and executing it to delete the data.

One thing to remember is that if the record you want to delete is the one side of a one-to-many relationship, you must change a property of that relationship before running the query. Later in this article, the Prepare to delete linked data section explains how to complete this task. Additional changes need to be made because, by default, Access prevents deletion of data on the one-side of a one-to-many relationship.

In addition, you need to remember that once you delete or update an entry or part of it, it is impossible to undo these changes, so you should always do backup copy data before executing the deletion request.

Note. Typically, update or delete queries are used only when you need to quickly update or delete a large amount of data. If you need to delete multiple records, and it's easier to do it manually, you can open the table in Datasheet view, select the fields or rows you want to delete, and press DELETE.

Planning for removal

The process of using a query to delete records includes the following basic steps.

Plan for removal. You should ensure that you have the necessary permissions to delete data and that other users have closed objects that use the relevant tables, and then back up the database.

Make sure the database is in a trusted location or signed digital signature. If none of these conditions are true, you can make the database trusted for the duration of your session. Remember that by default, Access blocks all change requests (delete, update, and create table) unless the database is set to trusted.

If you need to delete data from multiple tables and the tables are related, enable the Data Integrity and Cascading Delete Related Records options for each relationship. This will allow the query to delete data from tables on the one and many side of the relationship.

Create a select query and add conditions to retrieve the desired set of records.

If you need to remove individual fields from a table, convert the select query to an update query, enter a NULL value or an empty string

("") as the update condition and run the query.

If you want to delete entire records, convert the select query to a delete query and execute it.

Preparatory actions.

Before completely or partially deleting records from the database, follow these steps:

Make sure the database is not read-only. To do this, in Windows Explorer, right-click the database file (with the accdb or mdb extension) and select Properties from the context menu. In the Properties dialog box, the Read Only check box must be cleared. Verify that you have the necessary permissions to delete records from the database. Make sure that deleting entries will not affect the experience of other users. Ask all database users to close all tables, forms, queries, and reports that use the data to be deleted. This will avoid locking conflicts.

Advice. If the database is used by a large number of users, you may need to shut it down and reopen it with exclusive access.

Create a query to create a table.

Note. A query to create a table in a web database cannot be executed through a web browser. To do this, you need to open the web database in Access 2010.

A create table query is used when you need to copy the data contained in a table or create an archive of that data.

Create a query to create a table.

General information

A create table query retrieves data from one or more tables and then places the result set in a new table. The new table can be located in the database that is currently open, or it can be created in another database.

Typically, a query to create a table is used when it is necessary to copy data or place it in an archive. Let's assume that there is a table (or several tables) with historical sales data, and this data needs to be used in reports. The data cannot change, since all transactions were completed at least one day ago. Running a query multiple times to retrieve data takes a significant amount of time, especially if the query is complex and the data warehouse is large. By loading data into a separate table and using this table as a data source, you can reduce the load and get a convenient data archive. As you work, remember that the data in the new table is a copy of the original data at a certain point in time; they are not associated with the original table (or tables).

The procedure for creating a create table query includes the following basic steps:

Enable the database if it is not signed or in a trusted location. Otherwise, you will not be able to run change queries (queries to add, update, or create a table).

In query design mode, create a select query and modify it until it returns the records you want. You can select data from multiple tables and essentially denormalize it. For example, you can put customer, shipper, and supplier data into one table, which is not typically done in a production database with properly normalized tables. You can also use conditions in your query to fine-tune or narrow the result set.

Convert the select query to a create table query, select a location for the new table, and then run the query to create the table. Create a query to create a table. When writing a create table query, you must first create a select query and then convert it into a create table query. You can use calculated fields and expressions in your select query to ensure it returns the data you want.

Literature

1) Underdal, B. Self-instruction manual WINDOWS 98 – St. Petersburg: Peter 1998

2) Glushakov, S.V., Lomotko D.V. Databases: Training course - Kharkov: Folio, 2000

3) Eremin L.V. Kosarev V.P. Mashnikova O.V. Economic Informatics: Textbook