Summary of common SQL statement usage methods in MySQL

Create user

CREATE USER 'root'@'%' IDENTIFIED BY 'password';

Create user and grant specified permissions

grant create,select,update,insert,delete,alter on bbs.* to lvtao@localhost identified by 'password';

Create user and grant full permissions

Grant all privileges on *.* to 'root'@'%' identified by 'password' with grant option;

Create backup user

GRANT SELECT,RELOAD,SHOW DATABASES,LOCK TABLES,EVENT,REPLICATION CLIENT  ON *.* TO 'bak'@'localhost' IDENTIFIED BY 'password';

Back up all databases

mysqldump -u root -p --all-databases --ignore-database=performance_schema --ignore-database=information_schema --skip-lock-tables > /home/db.sql

Export a database structure

mysqldump -u root -p -d –add-drop-table database >/home/db.sql

Restore data

A:常用source 命令
进入mysql数据库控制台，
如mysql -u root -p
mysql>use 数据库
然后使用source命令，后面参数为脚本文件(如这里用到的.sql)
mysql>source wcnc_db.sql

B:使用mysqldump命令
mysqldump -u username -p dbname < filename.sql

C:使用mysql命令
mysql -u username -p -D dbname < filename.sql

Create database

create database <数据库名>;

Display all databases

show databases;

Delete database

drop database <数据库名>;

Select database

use <数据库名>;

View the currently used database

select database();

Table information contained in the current database:

show tables;

Create table

create table <表名> ( <字段名1> <类型1> [,..<字段名n> <类型n>]);

mysql> create table MyClass(
> id int(4) not null primary key auto_increment,
> name char(20) not null,
> sex int(4) not null default &#39;0&#39;,
> degree double(16,2));

Get the table structure

desc 表名，或者show columns from 表名

mysql>DESCRIBE MyClass;
mysql>desc MyClass; 
mysql>show columns from MyClass;

Delete the table

drop table <表名>

mysql> drop table MyClass;

Insert data

insert into <表名> [( <字段名1>[,..<字段名n > ])] values ( 值1 )[, ( 值n )]

mysql> insert into MyClass values(1,&#39;Tom&#39;,96.45),(2,&#39;Joan&#39;,82.99), (2,&#39;Wang&#39;, 96.59);

Query the data in the table

1)、查询所有行
命令： select <字段1，字段2，...> from < 表名 > where < 表达式 >
例如：查看表 MyClass 中所有数据
mysql> select * from MyClass;2）、查询前几行数据
例如：查看表 MyClass 中前2行数据
mysql> select * from MyClass order by id limit 0,2;
或者：
mysql> select * from MyClass limit 0,2;

Delete the data in the table

delete from 表名 where 表达式

mysql> delete from MyClass where id=1;

Modify the data in the table

update 表名 set 字段=新值,… where 条件

mysql> update MyClass set name='Mary' where id=1;

Add a field to the table:

alter table 表名 add字段 类型 其他; 

mysql> alter table MyClass add passtest int(4) default '0'

Change the table name:

rename table 原表名 to 新表名; 

mysql> rename table MyClass to YouClass;

Update field content

update 表名 set 字段名 = 新内容update 表名 set 字段名 = replace(字段名,'旧内容','新内容');
文章前面加入4个空格update article set content=concat('　　',content);

Update field part string

update contents set `text`=REPLACE(text,'http://www.lvtao.net','https://www.lvtao.net')

Field: Numeric type

Field: String type

Field: Date type