MySQL II: library operations

First, the system database

INFORMATION_SCHEMA: Virtual library, do not occupy disk space, storage is the database startup parameters, such as user table information, column information, permission information, character information, etc.

Performance_schema:mysql 5.5 started a new database: Mainly used to collect database server performance parameters, record the processing of query requests occurred in various events, locks and other phenomena

MySQL: Authorization Library, access information for primary storage system users

Test:database automatically created by MySQL database system

Second, create a database

1. Syntax (help create DATABASE)

CREATE database name CharSet UTF8;

2. Database naming rules:

Can consist of letters, numbers, underscores, @, #, $

Case sensitive

Uniqueness

You cannot use keywords such as create select

Numbers cannot be used alone

Maximum 128 bits

Third, database-related operations

1. View the database

show databases;

Show CREATE Database db1;

Select Database ();

2. Select Database

Use database name

3. Delete Database

DROP database name;

4. Modify the Database

ALTER DATABASE DB1 CharSet UTF8;

MySQL II: library operations