Summary of common SQL statement usage methods in MySQL-Mysql Tutorial-php.cn

Summary of common SQL statement usage methods in MySQL

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Release： 2017-02-11 14:51:14

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Create user

CREATE USER &#39;root&#39;@&#39;%&#39; IDENTIFIED BY &#39;password&#39;;

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Create user and grant specified permissions

grant create,select,update,insert,delete,alter on bbs.* to lvtao@localhost identified by &#39;password&#39;;

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Create user and grant full permissions

Grant all privileges on *.* to &#39;root&#39;@&#39;%&#39; identified by &#39;password&#39; with grant option;

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Create backup user

GRANT SELECT,RELOAD,SHOW DATABASES,LOCK TABLES,EVENT,REPLICATION CLIENT  ON *.* TO &#39;bak&#39;@&#39;localhost&#39; IDENTIFIED BY &#39;password&#39;;

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Back up all databases

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

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Export a database structure

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

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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

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Create database

create database <数据库名>;

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Display all databases

show databases;

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Delete database

drop database <数据库名>;

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Select database

use <数据库名>;

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View the currently used database

select database();

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Table information contained in the current database:

show tables;

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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));

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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;

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Delete the table

drop table <表名>

mysql> drop table MyClass;

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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);

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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;

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Delete the data in the table

delete from 表名 where 表达式

mysql> delete from MyClass where id=1;

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Modify the data in the table

update 表名 set 字段=新值,… where 条件

mysql> update MyClass set name=&#39;Mary&#39; where id=1;

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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 &#39;0&#39;

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Change the table name:

rename table 原表名 to 新表名; 

mysql> rename table MyClass to YouClass;

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Update field content

update 表名 set 字段名 = 新内容update 表名 set 字段名 = replace(字段名,&#39;旧内容&#39;,&#39;新内容&#39;);
文章前面加入4个空格update article set content=concat(&#39;　　&#39;,content);

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Update field part string

update contents set `text`=REPLACE(text,&#39;http://www.lvtao.net&#39;,&#39;https://www.lvtao.net&#39;)

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Field: Numeric type
Summary of common SQL statement usage methods in MySQL

Field: String type

Summary of common SQL statement usage methods in MySQL
Field: Date type