Question

我试图检索在不同条件下依赖的记录的数量。我得到了我预期的输出，但对我来说似乎很大。

select count(b.verificationdtl_gid) as received,
(
select count(b.verificationdtl_gid) 
from avs_trn_tverification a
inner join avs_trn_tverificationdtl b on a.verification_gid =b.verification_gid
inner join ver_mst_tverifier c on a.verifier_gid = c.verifier_gid
where c.verifier_gid='VFI1601203046' and b.sap_flag<>'Y'
)as Normal,
(
select count(b.verificationdtl_gid)
from avs_trn_tverification a
inner join avs_trn_tverificationdtl b on a.verification_gid =b.verification_gid
inner join ver_mst_tverifier c on a.verifier_gid = c.verifier_gid
where c.verifier_gid='VFI1601203046' and b.verification_status='Reject'
) as reject,
(
select count(b.verificationdtl_gid) 
from avs_trn_tverification a
inner join avs_trn_tverificationdtl b on a.verification_gid =b.verification_gid
inner join ver_mst_tverifier c on a.verifier_gid = c.verifier_gid
where c.verifier_gid='VFI1601203046' and b.verification_status='Decline'
)as decline
from avs_trn_tverification a
inner join avs_trn_tverificationdtl b on a.verification_gid =b.verification_gid
inner join ver_mst_tverifier c on a.verifier_gid = c.verifier_gid
where c.verifier_gid='VFI1601203046'

如果查询执行它会产生以下结果

  received    Normal      reject      decline
----------- ----------- ----------- -----------
33          24          0           2

Answer 1

改为使用条件聚合：

select
    count(b.verificationdtl_gid) as received,
    count(case when b.sap_flag <> 'Y' THEN b.verificationdtl_gid end) as Normal,
    count(case when b.verification_status ='Reject' THEN b.verificationdtl_gid end) as reject,
    count(case when b.verification_status ='Decline' THEN b.verificationdtl_gid end) as reject
from avs_trn_tverification a
inner join avs_trn_tverificationdtl b 
    on a.verification_gid = b.verification_gid
inner join ver_mst_tverifier c 
    on a.verifier_gid = c.verifier_gid
where
    c.verifier_gid = 'VFI1601203046'

是否有更好的方法来编写这个子查询，因为它似乎很大？

1 个答案: