2-1 library additions and deletions to change search

A database system

information_schema: virtual library, do not take up disk space and storage are some of the parameters of the database is started, as the user information table, column information, rights information, character information
performance_schema: MySQL 5.5 beginning a new database: mainly used for the collection database server performance parameters, record a variety of events that occur when processing a query request, lock phenomena
mysql: authorize, the main storage system user rights information
test database MySQL database system automatically created: test

Two to create the database

Syntax (help create database)

CREATE DATABASE 数据库名 charset utf8;

2 database naming rules:

可以由字母、数字、下划线、＠、＃、＄
区分大小写
唯一性
不能使用关键字如 create select
不能单独使用数字
最长128位

Three database-related actions

查看数据库
show databases;
show create database db1;
select database();
选择数据库
USE 数据库名
删除数据库
DROP DATABASE 数据库名;
修改数据库
alter database db1 charset utf8;