in能用多个字段去关联子查询吗错误：select policyno,itemkindno from tmp_policy_prp where(policyno,item
in能用多个字段去关联子查询吗
错误：
select policyno,itemkindno from tmp_policy_prp where
(policyno,itemkindno) not in (select policyno,itemkindno from tmp_policy_stat)
正确，但是效率不高：
select policyno,itemkindno from tmp_policy_prp t1 where not exists
(select 1 from tmp_policy_stat t2
where t1.policyno=t2.policyno
and t1.itemkindno=t2.itemkindno)
请问in能用多个字段去关联子查询吗
[解决办法]
多字段的没法用 in。
看看有木有reference，index