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多表多条件查询

select * from(select * from 表1 union all select * from 表2 union all select * from 表3 union all select * from 表4 union all select * from 表5)tb where 入职日期='2014-04-20' and 岗位='普工'

select * from sysobjects where type ='数据库名'

select * from abc where product name like '%存款与贷款%' 查询语句里面,字段名称可以带中括号,不能带引号.祝你成功!

select max(Aname),max(Adatetime),max(Btitle),max(Bdatetime ) from(select A.name Aname,A.datetime Adatetime,'' Btitle, '' Bdatetime from A where A.place=1 union allselect '','',B.title,B.datetime from B where B.place=1) T

select a.*,c.f from (select * from a inner join b on a.a = b.a) as a inner join c on a.d = c.d select a.*,c.f from a inner join b on a.a = b.a inner join b.d = b.d 两个都可以,第一个更容易理解 括号里的部分 是查询出 查询表a的数据和当表a的a=表b的a的数据,把这个结果集 再inner join c on a.d = c.d 查询出表b的d=表c的d 所对应的f的值.

select * from phome_ecms_memberpro where userid in( select userid from phome_ecms where checked >1 and id in ( select userid from phome_ecms_memberpro group by userid having count(userid)>4)) order by id asc --存储过程 效率更高些 这个写的不好.一般都不in查询 因为他的效率特别低.而且不需要全部字段的话,尽量就不用select * 来查询.慢慢努力哦!

select a.b_id,a.a_food,b.b_name from a inner join b on a.b_id = b.id where (a.a_food like '%肉%') and (b.b_name like '%肉%') 这样可以把量表中同时具有id的记录查出来.

既然没有任何关联,分开查询就好了,放在一起查询又怎么显示呢.select 字段 from (select * from shopa where place=1) as shopa,(select * from shopb where place=1) as shopb

给每个查询一个共同的栏位进行连接然后使用下面的语句就可以了 一次可以查询到三个表的相同条件的数量.不知道是不是你想要表达的意思 select a.qty1,b.qty2 from (select count(*) qty1 ,'d' YP_FormBG_ID from yp_form_relation_t ) a inner join (select count(*) qty2 ,'d' YP_FormBG_ID from yp_casewip_t ) b on a.YP_FormBG_ID=b.YP_FormBG_ID

首先看一下主表可不可以去掉重复的数据,然后在关联第二个表的时候,可以用distinct先去除重复的数据如:left outer join (select distinct productcat1_.id as productcat1_.id from qc_product_category productcat1_ ) B on seller.productCategory_id = B.productcat1_.id

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