tsql - 提高查询性能

Question

我有以下 sql 查询表现不佳：

SELECT 
    Count(ExtCardID) as CardCount 
from 
    CardIDs CARDS with (NoLock)
inner join 
    (select CustomerPK 
     from GroupMembership with (NoLock)
     where CustomerGroupID = 14 and Deleted = 0) as GM on GM.CustomerPK = CARDS.CustomerPK

上述连接中的以下Select部分返回了 800 万条记录：

select 
    CustomerPK from GroupMembership with (NoLock)
where 
    CustomerGroupID = 14 and Deleted = 0

有没有更好的方法来编写上面的sql代码？请指教。

Answer 1

您是否尝试过使用 LINQ？

LINQ 相当不错，而不是直接查询！

好文章