The structure of a simple databaseI

The structure of a simple database
If there is no data in the database (empty), it is a complete database, because it contains information about the structure of the base. Base structure defines the methods and the storage of their data in the database.
OBD may contain various objects. The main targets are the DB table. The simplest database has at least one table. The simplest structure is identical with the database structure is equal to its tables.
The structure of two-dimensional tables form the rows and columns. Their counterparts in the simplest structure, databases are the fields and records. If there are no records in the table, its structure is formed by a set of fields. Changing the composition of the fields in the underlying table (or properties), thus changing the structure of the data, and, consequently, get a new database.
The properties of the database fields
Database field not simply define the structure of the base-they still define the group that are recorded in the data property of a cell belonging to each of the fields. Listed below are the basic properties of fields in a database table for example Microsoft Access DATABASE ENGINE.
The name of the field-defines how to access this field when automated operations with the database (by default, the field names are used as column headings for tables).
The type field specifies the type of data that can be contained in this field.
Field size-determines the limiting length (in characters) of the data that can be stored in this field.
Format-determines how to format data in cells belonging to the field.
Input mask-determines the form in which you enter data in the field (data entry Automation).
Signature defines the table column heading for the field (if the signature is not specified, then the column header, use the name of the field).
The default value is the value that is entered in the cell field automatically (data entry Automation).
A value constraint used to validate data entry (typing automation tool, which is typically used for numeric data type, type or date type).
Error message-the text message that is issued automatically when the user tries to enter into the field of erroneous data.
Mandatory field is a property that identifies a data field is mandatory during the filling of the base.
Empty string property to allow empty string input data (from the required property that applies not to all types of data, but only to some text, for example).
Indexed field if the field has the property that all operations associated with the search or sort records based on the value that is stored in this field are accelerated significantly. In addition to indexed fields can be done so that the records will be checked on this field duplicates, that allows you to automatically delete the duplicate data.
Since different fields can contain data of various types, and properties of the fields may vary depending on the type of data. For example, a list of the above properties fields refers mainly to the fields of text type. Other field types may or may not have these properties, but may add to them and theirs. For example, for data representing real numbers, important property is the number of digits after the decimal point. On the other hand, for the fields that are used to store pictures, audio recordings, video clips and other OLE objects, the majority of the above properties do not make sense.
Data types
Database tables, usually allow for work with a much larger number of different data types. For example, a Microsoft Access database works with the following data types.
Text data type used to store the plain unformatted text of limited size (up to 255 characters).
Numeric data type for storing a real number.
The memo field is a special data type for storing large amounts of text (up to 65 535 characters).Text is not physically stored in the field. It is stored in a different location of the database and in a field a pointer to it, but for the user such a Division is not always noticeable.
Date/time data type to store calendar dates and the current time.
Cash-data type to store the cash. Theoretically, for their recordings could be used, and the numeric type fields, but for amounts of money there are some features (for example, associated with rounding rules) that make it more convenient to use a special type of data rather than setting numeric type.
The counter is a special data type for unique (non-recurring) of natural numbers with automatic build-up. Natural use is for ordinal numbering records.
Boolean-logical data storage type (can take only two values, such as Yes or no).
A hyperlink is a special field to store the URLs of Web objects on the Internet. When you click the link the browser starts automatically and playback object in its window.

Результаты (английский) 3:

the structure of a simple databaseif there is no data in the database (empty), it is a complete database, because it contains information about the structure of the base. base structure defines the methods and the storage of the data in the database.OBD may contain various objects. the main targets are the db table. the simplest database has at least one table. the simplest structure is identical with the database structure is equal to its tables.the structure of two dimensional tables form the rows and columns. the counterparts in the simplest structure, databases are the fields and records. if there are no records in the table, its structure is formed by a set of fields. changing the composition of the fields in the underlying table (or properties), thus changing the structure of the data, and consequently, get a new database.the properties of the database fieldsdatabase field not simply define the structure of the base they still define the group that are recorded in the data property of a cell belonging to each of the fields. listed below are the basic properties of fields in a database table for example microsoft access database englne.the name of the field - defines how to access this field when automated operations with the database (by default, the field names are used as column headings and tables).the type field specifies the type of data that can be contained in this field.field size, determines the limiting length (in characters) of the data that can be stored in this field.format - determines how to format data in cells belonging to the field.the input mask - determines the form in which you enter data in the field (data entry automation).signature defines the table column heading for the field (if the signature is not specified, then the column header, use the name of the field).the default value is the value that is entered in the cell field automatically (data entry automation).a value constraint used to validate data entry (typing automation tool, which is over used for numeric data type, type or date type.error message, the text message that is issued automatically when the user tries to enter into the field of erroneous data.mandatory field is a property that identifies a data field is mandatory during the filling of the base.empty string property to allow empty string input data (from the required property that applies not to all types of data, but only to some text, for example).Indexed field if the field has the property that all operations associated with the search or sort records based on the value that is stored in this field are accelerated significantly. in addition to indexed fields can be done so that the records will be checked on this field duplicates, that allows you to automatically delete the duplicate data.since different fields can contain data of various types, and properties of the fields may vary between on the type of data. for example, a list of the above properties fields refers mainly to the fields of text type. other field types may or may not have these properties, but may add to them and theirs. for example, for data representing real numbers, an important property is the number of digits after the decimal point. on the other hand, for the fields that are used to store pictures, audio recordings, video clips and other ole objects, the majority of the above properties do not make sense.data typesdatabase tables, usually allow for work with a much larger number of different data types. for example, a microsoft access database works with the following data types.text data type is used to store the unformatted plain text of limited size (up to 255 characters).numeric data type for storing (a real number.the memo field is a special data type for storing large amounts of text (up to 65 535 characters).Text is not physically stored in the field. it is stored in a different location of the database in a field and a pointer to it, but for the user, such a division is not always noticeable.date / time data type to store calendar dates and the current time.cash is the data type to store the cash. Theoretically, for their recordings could be used, and the numeric type fields, but for amounts of money there are some features (for example, associated with rounding rules) that make it more convenient to use a special type of data rather than setting numeric type.the counter is a special data type for unique (non recurring) of natural numbers with a build - up. natural use is for ordinal numbering records.boolean - logical data storage type (can take only two values, such as yes or no).a hyperlink is a special field to store the URLs of web objects on the internet. when you click the link, the browser starts automatically and playback object in its window.