Question

我需要在表中找到具有0溢价的策略，但是如果具有相同策略编号的另一个策略具有溢价则不需要。这是我的伪代码：

select * from tblPolicies where premium = 0
(but not if anther record has the same policyNumber and premium <> 0)

我知道这很可怕，但我迷路了，这是我能想到的最好的！

Answer 1

可能的查询1：

SELECT M.* FROM tblPolicies AS M
WHERE premium = 0 AND policyNumber NOT IN 
(
   SELECT S.policyNumber 
   FROM tblPolicies AS S 
   WHERE S.policyNumber = M.policyNumber
   AND S.premium <> 0 
)

可能的查询2：

SELECT SA.* FROM 
(
  SELECT M.* FROM tblPolicies AS M
  WHERE premium = 0
) AS SA
INNER JOIN tblPolicies AS SB
ON SA.policyNumber = SB.policyNumber 
WHERE SB.premium <> 0

可能的查询3：

SELECT * FROM tblPolicies AS SA
INNER JOIN tblPolicies AS SB
ON SA.policyNumber = SB.policyNumber 
WHERE SA.premium = 0 AND SB.premium <> 0

Answer 2

select p_no from 
(select p_no, sum(premium) as tot_prem from policy group by p_no) as pol 
where tot_prem>0;

p_no-＆GT;的 premium_no

policy-＆gt; 政策表

SQL子查询语法检查其他记录

2 个答案: