T-SQL參考查詢選擇日期

Question

我有以下SQL語句

Select * 
from Policies P 
inner join ClientPolicies CP on P.Id = CP.PolicyId 
where p.Id <> 0 
And  P.ProductId = 9 
And  (
    P.PolicyEndDate <= GETDATE() 
or 
    P.PolicyEndDate is null 
    ) 

這拉回所有符合第一policyendate小於GETDATE的值，而不是空值。

Answer 1

更改INNER JOIN到LEFT JOIN：

Select * 
from Policies P 
left join ClientPolicies CP on P.Id = CP.PolicyId 
where p.Id <> 0 
And  P.ProductId = 9 
And  (
    P.PolicyEndDate <= GETDATE() 
or 
    P.PolicyEndDate is null 
    )