mysql--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:mysql Database System Auto-created test database

Second, create a database

1. Syntax (help create databases)

Create database name CharSet Utf-8;

2. Data naming rules:

can be by letter, number, underscore, @, #, $ case-sensitive uniqueness cannot use keywords such as create select cannot use the number maximum 128 bits alone

Third, database-related operations

View database show databases;show CREATE DATABASE Db1;select database (); Select the databases use database name to delete database Dorp database name; ALTER DATABASE DB1 CharSet UTF8;

mysql--Library Operations