sql 多表联合查询语句

[yacity]

left join 语句后面 可以 跟多个表名吗?

如 select a.x,b.x,c.x from a left join b,c on a.y=b.y and a.y=c.y
请问这样的格式有问题吗？

[OracleRoob]

select a.x,b.x,c.x
from a
left join b on a.y=b.y
left join c on a.y=c.y

[xwqjamky]

select a.x,b.x,c.x from a,b,c where a.y=b.y and a.y=c.y

[xiyongjie]

up

[SoftwKLC]

上面两个答案都可以...UP

[fa_ge]

如 select a.x,b.x,c.x from a left join b,c on a.y=b.y and a.y=c.y
请问这样的格式有问题吗？

-------------------------------
这样不行地
select a.x,b.x,c.x from a left join b on a.y=b.y
left join c on a.y=c.y

[yuedeem]

jf

[y_dong119]

select a.x,b.x,c.x
from a
left join b on a.y=b.y
left join c on a.y=c.y

对的

[jiangsh100]

一楼那样子是行滴

use zgwpjh
go
select
b.catename,b.catecode,count(物品类别) as total
from products a inner join category b
on substring(a.物品类别,1,4)=b.catecode
inner join
用户 c on a.物品主人=c.用户名
where a.物品名称 like '%花%' and substring(a.物品类别,1,4)='1001'
and c.省份='山东' and c.城市='日照市'
group by a.物品类别,b.catename,b.catecode
order by total desc

你看我这样都行

[scow]

select a.x,b.x,c.x from a,b,c where a.y*=b.y and a.y*=c.y
--不推荐使用

[yangxia666]

select ci.CabIID,ci.CabTitle,ro.RoomName,hal.HallName,kc.KitchenName
from CabInfo as ci left join Room as ro on ro.RoomID=ci.RoomID
left join Hall as hal on hal.HallID=ci.HallID
left join Kitchen as kc on kc.KitchenID=ci.KitchenID
-----------------------
上面这样子对的。是可以查出来的