sms_1204 主表
msg_1204 是从表
用 id 关连着,id不是唯一的(sms_1204 和 msg_1204 的id 可重复)--第一种写法
select s.id,s.content,s.scount,mc.c from sms_1204 s,
(
select mpage.* from
(
select mid.*,rownum as rn from
(
select m.id,count(*) c from msg_1204 m where m.mstatus = 1 group by m.id
)mid
where rownum <=2000
)mpage
where mpage.rn >=0
)mc
where mc.id = s.id and s.fls_number=1
--第二种写法
select s.id,s.content,s.scount,mc.c from sms_1204 s,
(
select m.id,count(*)c from msg_1204 m ,
(
select spage.* from
(
select scondition.id, rownum as rn from
(
select s.id from sms_1204 s where s.fls_number = 1
)scondition
where rownum <=2000
)spage where spage.rn >=0
)sid
where sid.id = m.id and m.mstatus=1
group by m.id
) mc
where mc.id = s.id哪种条sql 效率高些,求解析
msg_1204 是从表
用 id 关连着,id不是唯一的(sms_1204 和 msg_1204 的id 可重复)--第一种写法
select s.id,s.content,s.scount,mc.c from sms_1204 s,
(
select mpage.* from
(
select mid.*,rownum as rn from
(
select m.id,count(*) c from msg_1204 m where m.mstatus = 1 group by m.id
)mid
where rownum <=2000
)mpage
where mpage.rn >=0
)mc
where mc.id = s.id and s.fls_number=1
--第二种写法
select s.id,s.content,s.scount,mc.c from sms_1204 s,
(
select m.id,count(*)c from msg_1204 m ,
(
select spage.* from
(
select scondition.id, rownum as rn from
(
select s.id from sms_1204 s where s.fls_number = 1
)scondition
where rownum <=2000
)spage where spage.rn >=0
)sid
where sid.id = m.id and m.mstatus=1
group by m.id
) mc
where mc.id = s.id哪种条sql 效率高些,求解析
解决方案 »
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