先粗略贴个出来探风,关注楼主动态./* 【多表外联查询(left join)】: a表和b表外联后,a表需要和c表外联, b表需要和d表外联;4张表有相同ID; 结果为每张表取出的一个字段组成,求语句 */select a.col col1, b.col col2, c.col col3, d.col col4 from a left join b on a.id=b.id left join c on a.id=c.id left join d on b.id=d.id
select * from a left join b on a.id=b.id left join c on a.id=c.id left join d on a.id=d.id
我晕,刚发帖自己就写出来了 select a.name,aa.Url,b.name,bb.Url from (a left join aa on a.ID=aa.ID) left join (b left join bb on b.ID=bb.ID) on a.ID=b.ID where a.ParentID=xx;谢谢大家咯
select a.col,b.col,c.col,d.col from a left join b on a.id=b.id left join c on a.id=c.id left join d on b.id=d.id
SQL code select a.col,b.col,c.col,d.col from a left join b on a.id=b.id left join c on a.id=c.id left join d on b.id=d.id [/Quote]
【多表外联查询(left join)】:
a表和b表外联后,a表需要和c表外联,
b表需要和d表外联;4张表有相同ID;
结果为每张表取出的一个字段组成,求语句
*/select
a.col col1,
b.col col2,
c.col col3,
d.col col4
from a
left join b
on a.id=b.id
left join c
on a.id=c.id
left join d
on b.id=d.id
from a left join b on a.id=b.id
left join c on a.id=c.id
left join d on a.id=d.id
select a.name,aa.Url,b.name,bb.Url
from (a left join aa on a.ID=aa.ID) left join (b left join bb on b.ID=bb.ID)
on a.ID=b.ID
where a.ParentID=xx;谢谢大家咯
select a.col,b.col,c.col,d.col
from a
left join b
on a.id=b.id
left join c
on a.id=c.id
left join d
on b.id=d.id
select a.col,b.col,c.col,d.col
from a
left join b
on a.id=b.id
left join c
on a.id=c.id
left join d
on b.id=d.id
[/Quote]