mysql 基本操作

插入数据

• insert into persons values('','','','')
• insert into persons (字段，字段，字段) values(value,value,value)

修改数据

• update 表名 set 字段=value where 字段=值

删除数据

• delete from 表名 where 字段=值

查询语句

• 查询 select * from 表名 where 字段=值
• top select top 2 * from 表名 查询前俩条数据
• where 条件
  • like 模糊查询 select * from 表名 where 字段 like '%n'
  • in select * from tb_name where 字段 in (value,value)
  • between select * from tb_name where 字段 between (value,value)
• order by select * from tb_name order by 字段 desc desc asc

多表查询

• select a.字段,b.字段 from tb_namea as a,tb_nameb as b where a.id=b.id
• SELECT Persons.LastName, Persons.FirstName, Orders.OrderNo FROM Persons INNER JOIN Orders ON Persons.Id_P = Orders.Id_P
• union合并俩个查询结果 SELECT E_Name FROM Employees_China UNION SELECT E_Name FROM Employees_USA;

关键字

• primary key 主键
• auto_increment 自增