储存过程多个表比较的修改！

[v1srine]

列子：
select a.*,b.* from #temppd a left join #tempbom b on a.item_code=b.item_code

这句代码 还可以加第三个表嘛?
怎么加。
这里只有两个表对比。但是我想在这段代码里面加上第三个表对比请问怎么加？
我试了很久都没结果！
求答案！

select a.mater_code,a.pdwet,c.jieguo as gxwet,a.mtwet,a.mtgmawet,b.item_order  from 
(select a.mater_code,sum(case when TAG='A' then wet else 0 end) as pdwet,
sum(case when TAG='包根' then wet else 0 end) as gxwet,
sum(case when TAG='GC' then wet else 0 end) AS mtwet,
sum(case when TAG='GMA' then wet else 0 end) AS mtGMAwet
 from 
(select b.mater_code,sum(round(a.wet*b.len_xs,2)) as wet,tag from #temppd a left join #tempbom b on a.item_code=b.item_code
where b.class_code=2 and b.mater_code is not null group by b.mater_code,a.tag
union all
select b.mater_code,sum((a.wet*b.len_xs/100)) as wet, '包根' AS tag from #temppd_gx a left join tempbom b on a.item_code=b.item_code
where b.class_code=1  and b.mater_code is not null group by b.mater_code
union all
select item_code as mater_code,wet,packno AS tag from #temppd_mt
) a group by a.mater_code,a.tag
)a left join fourk.dbo.item b on a.mater_code=b.item_code 
order by item_order

我这段代码怎么加！
我 c.jieguo as gxwet
这个C 我想加个表！
但是不知道怎么加上去
这是储存过程！

[Billy]

select * 
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

可以任意加多少

[v1srine]

2楼，我想知道我的代码怎么加？

你的那个我老早试过了，我加不上！

希望你能帮帮忙

[wing7742]

没看到你表C在哪

[v1srine]

表C。.
C 是缩写

#tempssS c

这个是表C。请问怎么加？

[jxqn_liu]

子查询嵌套子查询，建议优化下，把一些查询改成视图等
再说你要加的C表要加那个位置得看你得实现啥功能先。