MySQL增删查改基本命令

1、建立数据库

语法：create database 数据库名；
实例：
mysql> create database shujuku;

Query OK, 1 row affected (0.10 sec)

2、进入数据库

语法：use 数据库名；
实例：
mysql> use shujuku;

Database changed

3、新建表

语法：create table 表名(字段，...);
实例：
mysql> CREATE TABLE class1 (

    -> id SMALLINT UNSIGNED AUTO_INCREMENT ,

    -> name VARCHAR(30) NOT NULL UNIQUE KEY ,

    ->  school VARCHAR(30) DEFAULT 'jilin_university',

    ->  PRIMARY KEY(id)

    -> );

Query OK, 0 rows affected (0.18 sec)

4、查看表结构

语法： desc 表名;
实例：
mysql> desc class1;

+--------+----------------------+------+-----+------------------+----------------+

| Field  | Type                 | Null | Key | Default          | Extra                   |

+--------+----------------------+------+-----+------------------+----------------+

| id     | smallint(5) unsigned | NO   | PRI | NULL             | auto_increment |

| name   | varchar(30)          | NO   | UNI | NULL             |                            |

| school | varchar(30)          | YES  |     | jilin_university |                             |

+--------+----------------------+------+-----+------------------+----------------+

3 rows in set (0.05 sec)

5、插入

语法：insert into 表名 set 字段名=‘字段值’,...;
实例：
mysql> insert into class1 set name='baiyang',school='nanhugaozhong';

Query OK, 1 row affected (0.00 sec)

mysql> insert into class1 set name='yueyue';

Query OK, 1 row affected (0.00 sec)

6、修改

语法：update 表名 set 字段=‘修改值’ where 字段=‘原值’,...;
实例：
mysql> update class1 set name='lala' where name='yueyue';

Query OK, 1 row affected (0.04 sec)

Rows matched: 1  Changed: 1  Warnings: 0

mysql> select * from class1;

+----+---------+------------------+

| id | name    | school           |

+----+---------+------------------+

|  1 | baiyang | nanhugaozhong    |

|  2 | lala    | jilin_university |

+----+---------+------------------+

2 rows in set (0.00 sec)

7、删除

语法：delete from 表名 where 条件;
实例：
mysql> delete from class1 where school='jilin_university';

Query OK, 1 row affected (0.00 sec)

mysql> select * from class1;

+----+---------+---------------+

| id | name    | school        |

+----+---------+---------------+

|  1 | baiyang | nanhugaozhong |

+----+---------+---------------+

1 row in set (0.00 sec)

语法：drop table 表名;
实例：
mysql> drop table class1;

Query OK, 0 rows affected (0.01 sec)

语法：drop database 数据库名;
实例：
mysql> drop database shujuku;

Query OK, 0 rows affected (0.36 sec)

8、查询

语法：select * from 表名;     简单查询
实例：
mysql> select * from class1;

+----+---------+------------------+

| id | name    | school             |

+----+---------+------------------+

|  1 | baiyang | nanhugaozhong    |

|  2 | yueyue  | jilin_university        |

+----+---------+------------------+

2 rows in set (0.00 sec)

语法：select * from 表名 where 条件;     条件查询
实例：
mysql> select * from class1 where id>1;

+----+--------+------------------+

| id | name   | school           |

+----+--------+------------------+

|  2 | yueyue | jilin_university |

+----+--------+------------------+

1 row in set (0.06 sec)

语法：select * from 表名 group by 字段 desc;    分组查询
实例：
mysql> select * from class1 group by school desc;

+----+---------+------------------+

| id | name    | school           |

+----+---------+------------------+

|  1 | baiyang | nanhugaozhong    |

|  2 | yueyue  | jilin_university |

+----+---------+------------------+

2 rows in set (0.06 sec)

语法：select * from 表名 order by 字段 desc;   排序查询，升序asc,降序desc
实例：
mysql> select * from class1 order by id desc;

+----+---------+------------------+

| id | name    | school           |

+----+---------+------------------+

|  2 | yueyue  | jilin_university |

|  1 | baiyang | nanhugaozhong    |

+----+---------+------------------+

2 rows in set (0.00 sec)