|
1.关于exists和in
in是循环的方式，在内存中处理，
exists是执行数据库查询，
?
select tpd.personaccountid,sum(nvl(tpd.CREDIT_SUM,0)) as bjsr,sum(nvl(tpd.INTEREST_INCOME,sum(nvl(tpd.DEBIT_SUM,0)) as bjzc from TGP_PERSON_DETAIL tpd
left join TAP_FUNDBUSINESS tfb
on tpd.FUNDBUSINESS_ID = tfb.FUNDBUSINESS_ID
where tpd.PERSONACCOUNTID
in (
select personaccountid from TGP_PERSONACCOUNT pa
left join tgp_person person
on pa.personid = person.personid
where person.zjhm = ‘330903196209160251‘
) group by tpd.personaccountid
执行100次 耗时0.017S左右
?
select tpd.personaccountid,0)) as bjzc from TGP_PERSON_DETAIL tpd
left join TAP_FUNDBUSINESS tfb
on tpd.FUNDBUSINESS_ID = tfb.FUNDBUSINESS_ID
where
exists (
select personaccountid from (select personaccountid from TGP_PERSONACCOUNT pa
left join tgp_person person
on pa.personid = person.personid
where person.zjhm = ‘330903196209160251‘) a
where tpd.personaccountid = a.personaccountid
) group by tpd.personaccountid
执行100次 耗时0.020S左右
以上都为SELECT FORM a IN b(OR EXISTS B)? B中数据少的时候 采用IN 多的时候采用EXISTS??
?
select tpd.personaccountid,0)) as bjzc from TGP_PERSON_DETAIL tpd
left join TAP_FUNDBUSINESS tfb
on tpd.FUNDBUSINESS_ID = tfb.FUNDBUSINESS_ID
HAVING
exists (
select personaccountid from (select personaccountid from TGP_PERSONACCOUNT pa
left join tgp_person person
on pa.personid = person.personid
where person.zjhm = ‘330903196209160251‘) a
where tpd.personaccountid = a.personaccountid
) group by tpd.personaccountid
执行100次 耗时2.36S左右
因此先筛选数据再分组 效率更高
（编辑：李大同）
【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容!
|
