sql - 如何根据条件选择列？

Question

我有一个名为 @status 的变量，我在这个 select 语句之前设置了它:

Select
ordr_num as num,
ordr_date as date,
ordr_ship_with as shipwith
From
order
where ordr_num = @ordrNum

我只想选择 ordr_ship_with列如果 @status <> 'Cancelled' ，否则我想为发货选择 null。我该如何实现？

Answer 1

SELECT ordr_num as num, ordr_date as date, 
    CASE WHEN @status<>'Cancelled' THEN ordr_ship_with ELSE NULL END as shipwith 
FROM order 
WHERE ordr_num = @ordrNum