There are many definitions Database, by this concept we will understand the following:

Database ─ a file (document) in which information (data) is stored in a special format.

Other database definitions.

Database:

A data file with a specific structure.

A named collection of interrelated data of a certain subject area.

Some unified collection of data shared by a group of people.

Electronic repositories of information that are accessed using one or more computers.

Interrelated information (data) about objects that is specially organized and stored in the external memory of a computer.

An information model that allows you to orderly store data about a group of objects that have the same set of properties.

Types of Database Models

Hierarchical;

There are connections between objects. One element is considered the main one, the rest are subordinate. Each object can include several objects more than low level. Graphically it represents a tree consisting of objects of various levels.

Network;

It is a generalization of the hierarchical one due to the assumption of objects that have more than one ancestor.

Relational;

The most common one is a generalization of the network and hierarchical database model. Consists of one or more interconnected two-dimensional tables.

Table row - object instance (record);

Table column - object attribute (field).

There can be relationships between tables according to the principal (parent, master) - subordinate (child, detail) principle.

Database management systems

DBMS ─ a software system that allows you to create a database, update the information stored in it, providing easy access to it for the purpose of viewing and searching.

Other definitions of DBMS.

DBMS ─ software, intended for:

description of data, operation (manipulation) of data;

data management in external memory;

control of data protection and integrity, control of simultaneous access;

service operations on data (administration, archiving, etc.).

DBMS─ a set of software tools designed to create a database structure, fill and edit its contents and for visualizing information, i.e. for selecting data that meets specified criteria, sorting it and displaying it on a screen, printer or transmission over computer networks.

DBMS─ a program with the help of which information is entered into the database, viewed, sorted, filtered, searched, exported (translated into the formats of other DBMSs) or imported.

DBMS ─ software, designed to work with databases.

Types of subdata

By execution method:

universal (Access);

specialized (1C);

By data access method:

• local (dBase; Access; Paradox);

  network, distributed (DB Servers: MS SQL Server, InterBase, Oracle, PostgreSQL).

Capabilities and purpose of the subdatabase

The main purpose of a DBMS is to provide the user with a simple and accessible tool that will allow him to create the databases that he needs.

To work with a database, the DBMS must provide:

the ability to enter and read information;

working with large amounts of data;

speed of data retrieval;

data integrity (their consistency);

protection from destruction, destruction, and unauthorized access;

a system of friendly prompts (based on a user without special training).

Let's take a closer look at the types of database models.

Development of database forms

For information security a window was created for entering your login and password (Figure 2.3).

Figure 2.3 - Database login window

After logging into the system, the main page of the database is displayed, on which 3 Buttons are located to access the program modules, as well as a DBGrid, displaying basic information about the current hotel guests. (Figure 2.4)

Figure 2.4 - Main page of the database

Figure 2.5 - Request module

The form contains 4 ready-made SQL queries that will be necessary for the hotel administrator. RadioButton components are used to switch between requests. There are 2 buttons on the form to return to Home page and to go to view the entire database. Program code in Appendix A

There is also a form for viewing all databases. You can go to it after clicking the “View DB” button. (Figure 2.6)

Figure 2.6 - Database viewing form

On the form we placed 4 RadioButton components for switching between tables, a DBGrid component for viewing data from tables, and a DBNavigator component for managing, adding, editing and deleting records in the database. There is also a button to go to the requests module - the “Go to requests” button.

For databases, the ability to create a printable report is very important. Therefore, we added a form for reports to the program (click on the “Report” button). The report was created using the components of the QuickReport tab. Report window under development. (Figure 2.7)

To remove necessary information into the report, we used an SQL query. The query itself is written inside the ADOQuery component in the SQL property. The ADOQuery component receives information from the DM data module, which we connected to the form using the “File > Use Unit...” command. On the QuickReport form, the properties included the following lines: PageHeader (the header, which contains the date and time of report creation), Title (the name of the report is written down), ColumnHeader (the names of the columns for records are written down), Detail (used to fill the report with data from the database), PageFooter (Report pages indicated). To receive and fill data from ADOQuery, we used the QRDBText components; in the properties we set: DataSet - connection to ADOQuery, DataField - the necessary columns from the database. QRlabel was also used for various signatures. The program code and request text are in Appendix A.

Figure 2.7 - Report form

After the above steps, we received a finished report (Figure 2.8)

Figure 2.8 - Finished report

Creation of an online help system

DrExplane is a very easy to use help authoring tool. Without necessary knowledge, you can quickly create HTML Help (CHM), Web Help, PDF, and Word documents with a wizard.

Ready help (Figure 2.9)

Figure 2.9 - Help

Option No. 2 - DB "Airport".
Formulation of the problem. Create an “Airport” database containing information about flights at various airports.
1. The database must contain the following information:
- “Airport” table containing the following information about various airports: City, Name.
- “Aircraft” table containing information about aircraft: Model, Capacity.
- The “Passengers” table containing information about passengers: Last name, First name, Patronymic, Gender, Passport No., Citizenship.
- The “Flights” table containing information about flights: Day of the week, Departure time, Aircraft code, Passenger code, Airport code.
2. Define primary and secondary (foreign) keys (add fields if necessary). Entering data into fields foreign key, as well as in fields with a small set of possible values, organize using the substitution wizard, and also provide an input mask where possible.
3. Establish a relationship between tables, providing for data integrity, cascading updates of related fields, and cascading deletion of related records.
4. Enter at least 4 records into tables without a foreign key and at least 10 records into tables containing a foreign key field.
5. Create the following queries, giving them meaningful names.
- Sample request. To display information about passengers who booked a ticket to Washington. Display the following fields on the screen: Day of the week, Last name, First name, Passport number, Citizenship.
- Request for group operations. To display the total number of passengers from three random countries. Display the following fields: Citizenship, Total number of passengers.
- Parametric query. To display the Last Name, First Name, Passport No., Citizenship of passengers at the airport specified by the “name” parameter.
- Cross request. To display information about the number of passengers at various airports of a particular aircraft model.
- Request to create a table. To create the "Planes 1" table, make a copy of the "Planes" table. Delete information about F-117 aircraft from the created table by implementing a delete request.
- Request for deletion. To remove information from the "Passengers" table for passengers from Japan.
6. Create the following forms, giving them meaningful names.
- A subform displaying data from the “Passengers” and “Flights” tables. Add buttons to the created form to move between records.
- Create a form displaying the following information: Last name, First name, Passenger passport number, Day of the week of the flight and Aircraft model. Add Departure Time to the notes area.
7. Create a report displaying the following information about flights: Last Name, First Name, Passenger Passport No., Flight Weekday and Airport City Name. In the footer, add your last name, group number and the date the database was created.
8. Create macros to open all database tables. Give meaningful names to macros.
9. In design mode, create a form " User interface", allowing you to work with the created database. The form displays information about the name of the database and the author. Place on form command buttons, allowing you to open all tables, queries, forms and reports and set meaningful names for them. Edit the form using the Toolbox drawing controls. Place your photo on it.
10.Create a macro to automatically open the “User Interface” form.

This database is not yet available, but can be ordered

You need to create a shell to work offline with various types reference books.

All directories are divided into two types - databases and directories in html format.

The directory files themselves (structure) need to be developed based on my wishes. That is, it turns out that you need to develop a shell and a file format that is “understood” by the shell.

The shell must be able to connect these directories, search them, create selections from the database, export records, sort records, edit, enter own recordings and changes. The shell also provides for the operation of a record classifier and the creation of your own classifier (hereinafter called “user groups”).

As additional features it is planned to develop a module for printing address data on envelopes, creating electronic diary, calculator.

The purpose of the shell is to work with a large number of different databases. The main database is a database of Russian enterprises.

Directory in the form of a database.

The basis of such a directory is data tables. The main table and connected tables (based on the same principle as in access).

For example, there is a main table with the following fields:

Company name

City code

Gas station

Ekaterinburg, Lenina, 1

Omsk, Mira, 44

Moscow, trading, 23

The fields marked with * in the example are index fields, i.e. there are two more tables that contain the decoding of these indexes.

Region index

Moscow city

City index

Decoding

Ekaterinburg

In the shell, when working with the directory, already decrypted data is displayed. These index tables are made to reduce the size of the reference book. After all, for example, the entry “Sverdlovsk Region” can appear in the database seventy to eighty thousand times.

The above example is for reference only; in fact, the tables are larger and the number of fields is greater.

For each such directory there is a “record classifier” table, i.e. an index field that assigns a record to a particular group. The classifier itself (list) is placed in separate window on the shell desktop. When you select a record from the classifier, a selection of records is made from the database and only those that satisfy the condition are displayed.

The directory file itself consists of several parts: the tables themselves and the following information:

Technical data of the reference book: title, description, author, date last update, cost, path of the page of this directory on the site (hyperlink).

Listing the functions that should work in the shell with this reference.

List of fields for which a “quick search” is carried out.

Record card layout.

Layout of the form for printing entries from the directory.

License information

Record classifier table

It is planned to make the reference file itself on xml based, but here it is at the discretion of the developer. The main thing is that this format is understandable to the shell and the directory is connected correctly.

When connecting a directory, the shell reads all the data, transfers all tables to its directory, and organizes connections between tables. And all the functions for working with the directory are connected: search, selection, export, etc.

Directory in formathtml.

This type of reference book is a set of pages and pictures. To navigate through this directory, a menu file is used, the contents of which are placed in the classifier window. To work with such a directory, you need to build a simple browser into the shell. All data (pages and pictures) for the directory will be contained in the directory file; the shell does not require access to the Internet.

The requirements for the operation of the shell should be the most minimal: big list operating systems(at the initial stage you can limit yourself to Windows 9x, 2000, NT, XP), as simple as possible the technical data of the computer ( RAM, processor), should not require additional drivers or programs installed. Everything necessary for the shell to work must be installed from the distribution.

All functions must be accessible and understandable to use by the average user.

List of all shell functions:

Directory

Connect directory

Delete directory

List of all available directories

Directory 1

Directory 2

Directory 3

Extended list of installed directories

Quick search

Advanced Search

Search found

Move entry to “Pocket”

Clear "Pocket"

Add a note

Delete entry

Edit entry

Importing data into the directory

Go to next entry

Go to previous post

Sort records in ascending order AàA

Sort records in descending order YАА

Printing settings

Print selection

Editing the output form

Envelope printing

Calculator

Diary

Working with groups

Create a group

Edit group

Delete a group

Add an entry to a group

Remove an entry from a group

About the program

Get a list of all available directories

Full Terms of Reference described appearance programs (location of all windows, menu items), Full description directory file structure, description of settings, process of connecting the directory, etc.

Please note that I need a program for distribution on a CD, and not Internet engines.

Unfortunately, the developer who made the shell for me disappeared somewhere without a trace, but he managed to develop the program interface. It’s not entirely true, but it will be enough to understand what I need.