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This article mainly explains "what is the meaning of the database". The content of the explanation in the article is simple and clear, and it is easy to learn and understand. let's follow the editor's train of thought to study and learn "what is the meaning of the database"!

Basic concepts of database

A database is a collection of data stored in some organized way. A database (database) is a container for holding organized data. Database management system (DBMS) is a kind of database software, MySQL is a kind of DBMS, that is, it is a kind of database software, the database management system used by the author is MySQL, except for special instructions, all the database software used by the author is MySQL.

Here are some basic concepts of the database, such as "table", "schema", "column", "row", "primary key" and so on.

Table (table) A structured list of a particular type of data, a structured file that can be used to store a particular type of data. Schema information about the layout and characteristics of databases and tables. Column (column) A field in the table. All tables consist of one or more columns. A record in the row table. The primary key (primary key) is a column (or set of columns) whose values uniquely identify each row in the table. Any column in a table can be used as a primary key as long as it satisfies the following conditions: no two rows have the same primary key value; each row must have a primary key value (the primary key column does not allow NULL values); the values in the primary key column are not allowed to be modified or updated; the primary key value cannot be reused (if a row is deleted from the table, its primary key cannot be assigned to a future new row)

Structured query language

SQL is the abbreviation of structured query language (Structured Query Language). SQL is a language designed to communicate with databases.

Advantages of SQL statement

SQL is not a language proprietary to a particular database vendor. Almost all important DBMS supports SQL, so learning this language enables you to deal with almost all databases

SQL is easy to learn. Its sentences are all made up of highly descriptive English words, and the number of these words is small.

Simple as it may seem, SQL is actually a powerful language that uses its language elements flexibly and can perform very complex and advanced database operations.

Advantages of MySQL

The cost of learning is low. MySQL is open source and can be used free of charge.

The code runs fast and the MySQL executes quickly.

Trust is high. Some very important and prestigious companies and sites use MySQL. These companies and sites all use MySQL to process their important data.

Easy to use, MySQL is easy to install and use.

Mysql command line utility

To specify the user login name root, you should use mysql-u root. -u is followed by the user name we want to log in. In order to give the user name, hostname, port, and password, we should use mysql-u root-p-h myserver-P 123456 and follow the login password.

A complete list of command-line options and arguments is available with mysql-- help.

The command is entered after mysql >

The command ends with; or\ g, in other words, just press Enter and do not execute the command

Enter help or\ h for help, or you can enter more text for help with a specific command (for example, enter help select for help using the SELECT statement)

Type quit or exit to exit the command line utility.

SQL data type

The type of data allowed by the data type (datatype) Each table column has a corresponding data type, which limits (or allows) the data stored in the column. Common data types are string, numeric, date and time, and binary data types.

String data type

Numeric data type

Date and time data type

Binary data type

Thank you for your reading, the above is the content of "what is the meaning of the database", after the study of this article, I believe you have a deeper understanding of what the meaning of the database is, and the specific use needs to be verified in practice. Here is, the editor will push for you more related knowledge points of the article, welcome to follow!

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