手上没有事业线的女人:access的多于两个表的数据查询的sql语句怎么写?

来源:百度文库 编辑:高校问答 时间:2024/04/29 03:32:26
select a.studentname,a.zhengpic,b.getbookdate from studentinfo as a left join bookinfo as b on a.id=b.studentid

上面是两个表的查询,多于两个表的怎么写?

select a.studentname,a.zhengpic,b.getbookdate from studentinfo as a ,bookinfo as b ,booktype as c on a.id=b.studentid and b.id=c.id

select * from a left join b on a.id=b.a_id left join c on b.id=c.b_id
3个表了

多join 连接就行了..

select a.studentname,a.zhengpic,b.getbookdate
from studentinfo a and bookinfo b
if a.id=b.studentid