select * from Img union all select * from Images where PersonID='231027197112226617' or ID='001523198203050016' or ID='13072119740408082X' or ID='220622197104120028'
Img 表为空,符合记录的也只有Images表里有4条记录,但联合表一搜索出来的记录有好几十条(几十条都是无关的记录),为什么??
select * from Images where ID='231027197112226617' or ID='001523198203050016' or ID='13072119740408082X' or ID='220622197104120028' (搜索出4条记录)
Img 表为空,符合记录的也只有Images表里有4条记录,但联合表一搜索出来的记录有好几十条(几十条都是无关的记录),为什么??
select * from Images where ID='231027197112226617' or ID='001523198203050016' or ID='13072119740408082X' or ID='220622197104120028' (搜索出4条记录)
select * from Img union select * from Images where PersonID='231027197112226617' or ID='001523198203050016' or ID='13072119740408082X' or ID='220622197104120028'
--注意union all和union的区别select * from Img union select * from Images where PersonID='231027197112226617' or ID in('001523198203050016' ,'13072119740408082X' ,'220622197104120028')
select * from Img union all select * from Images where PersonID='231027197112226617' or ID='001523198203050016' or ID='13072119740408082X' or ID='220622197104120028'中的PersonID应该为ID
image 数据类型不能选为 DISTINCT,因为它不可比。
union
select ID from Img where ID='231027197112226617' or ID='001523198203050016' or ID='13072119740408082X' or ID='220622197104120028'这样看应该清楚一点儿,你现在的where条件是针对Img表的,根本不会对Images表产生筛选的作用
union select * from Images where PersonID='231027197112226617'