mysql操作数据库语句整理(方便以后使用)

1 :any的用法

表结构如下:(如果表没有关系,这个也就没用处)

班级表:



学生表



=any相当于in语句 相等的意思

select * from classstu where class_Id=any(select class_id from student);

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

| class_Id | class_name |

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

| 1 | 1232 |

| 2 | 一年级 |

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

2 rows in set

>any 大于any的意思就是大于等于最大的

select * from classstu where class_Id>any(select class_id from student);

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

| class_Id | class_name |

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

| 2 | 一年级 |

| 3 | 二年级 |

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

2 rows in set

mysql>

<any的意思小于等于最小的包含的意思

select * from classstu where class_Id<any(select class_id from student);

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

| class_Id | class_name |

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

| 1 | 1232 |

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

1 row in set

第二点:join的用法

inner join 内连接 跟join的用法类似.将多张表符合条件的都列出来

select * from classstu join student using(class_Id);

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

| class_Id | class_name | studentID | name | age |

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

| 1 | 1232 | 1 | 一班059 | 25 |

| 1 | 1232 | 2 | 一班059 | 25 |

| 1 | 1232 | 3 | 一班059 | 25 |

| 1 | 1232 | 4 | 一班059 | 25 |

| 1 | 1232 | 5 | 一班059 | 25 |

| 2 | 一年级 | 6 | 二班059 | 25 |

| 2 | 一年级 | 7 | 二班059 | 25 |

| 2 | 一年级 | 8 | 二班059 | 25 |

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

2:left join on的用法

select * from classstu left

join student using(class_Id);

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

| class_Id | class_name | studentID | name | age |

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

| 1 | 1232 | 1 | 一班059 | 25 |

| 1 | 1232 | 2 | 一班059 | 25 |

| 1 | 1232 | 3 | 一班059 | 25 |

| 1 | 1232 | 4 | 一班059 | 25 |

| 1 | 1232 | 5 | 一班059 | 25 |

| 2 | 一年级 | 6 | 二班059 | 25 |

| 2 | 一年级 | 7 | 二班059 | 25 |

| 2 | 一年级 | 8 | 二班059 | 25 |

| 3 | 二年级 | NULL | NULL | NULL |

他的意思是将 前者的表中的数据全部列出 后者必须满足条件

3 right join on的用法 是依赖于后者. 必须满足后者的条件

select * from classstu right

join student using(class_Id);

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

| class_id | studentID | name | age | class_name |

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

| 1 | 1 | 一班059 | 25 | 1232 |

| 1 | 2 | 一班059 | 25 | 1232 |

| 1 | 3 | 一班059 | 25 | 1232 |

| 1 | 4 | 一班059 | 25 | 1232 |

| 1 | 5 | 一班059 | 25 | 1232 |

| 2 | 6 | 二班059 | 25 | 一年级 |

| 2 | 7 | 二班059 | 25 | 一年级 |

| 2 | 8 | 二班059 | 25 | 一年级 |

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

8 rows in set