mysql怎样让表竖立衔接?【MySQL教程】,mysql,表
1.内衔接
内衔接就是表间的主键和外键相连,只获得键值一致的数据的衔接体式格局。
细致语法:
Select 列名1…from 表1 inner join 表2 on 表1.外键=表2.主键 [where /order by 语句]
举个栗子:
建立class 数据库和student 、goods两个表和响应字段,个中student作为主表,它的外键goodsID和goods表的主键id对应,查询语句(个中把表名student记为s, goods记为g轻易援用)
select s.name,s.phonenumber,g.name from student as s inner join goods as g on s.goodsID=g.ID;
2.多个表的内衔接
下面经由过程设置外键将四个表的数据衔接起来。
select s.name,s.phonenumber,s.sex,g.name,c.classname,a.address from ((student as s inner join goods as g on s.goodsID=g.ID)inner join classname as c on s.ID=c.ID)inner join address as a on c.ID=a.ID;
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