如果两列都不是 NULL，我如何获得 SQL 'When' 子句以仅 return concat 数据？

Question

我在 SQL 服务器中有以下代码：

[siteWindowStart] = case
        when loc.LOCATION_TYPE_ID = '1'
        and ps.STOP_PLANNED_START_DATE is null
            then concat(pt.[TOUR_PLANNED_START_DATE], 'T', '09:00:00')
        when loc.LOCATION_TYPE_ID = '1'
        and ps.STOP_PLANNED_START_DATE is not null
            then concat(ps.STOP_PLANNED_START_DATE, 'T', '09:00:00')
        when loc.LOCATION_TYPE_ID in  ('6', '7', '8')
        and ps.STOP_REQUIRED_DELIVERY_DATE is not null
            then concat(dateadd(day, -1, ps.STOP_REQUIRED_DELIVERY_DATE), 'T' ,ps.[STOP_REQUIRED_DELIVERY_TIME])
        when loc.LOCATION_TYPE_ID in ('6', '7', '8')
        and ps.STOP_REQUIRED_DELIVERY_DATE is null
            then CONCAT(dateadd(day, -1, pt.[TOUR_PLANNED_START_DATE]), 'T', pt.[TOUR_PLANNED_START_TIME])
        else null
        end

对于这部分代码...

and  ps.STOP_REQUIRED_DELIVERY_DATE is not null
            then concat(ps.STOP_REQUIRED_DELIVERY_DATE, 'T', dateadd(minute, 30, ps.[STOP_REQUIRED_DELIVERY_TIME]))

如果 ps.stop_required_delivery_date 和 ps.stop_required_delivery_time 都不为空，我需要确保它仅 return 是 concat。

我尝试添加：

and ps.stop_required_delivery_time is not null

但这只是 returned else 语句，即 'NULL' !

如果两列都不为空，我如何将其编码为仅return concat 文本？如果一个为空而另一个已填充 return

then concat(pt.[TOUR_PLANNED_START_DATE], 'T', dateadd(minute, 30, pt.[TOUR_PLANNED_START_TIME]))

非常感谢

Answer 1

IS NULL 和 IS NOT NULL 在 CASE 中完美工作，如下例所示。
我已经使用数据类型日期和时间使其尽可能接近您的情况，而无需您的 table 定义和示例数据。

CREATE TABLE t ( a date, b time);
insert into t values ('2022-01-01','10:00'),('2022-01-01',null),(null,'10:00'),(null,null);

GO

4 rows affected

select  
        a,
        b,
        case
        when a is not null and b is not null then concat(a,'T',b)
        when a is not null and b is null then 'a-null'
        when a is null and b is not null then 'null-b'
        when a is null and b is null then 'null-null'
        else 'not possible' 
        end "a-b"
  from t
GO

a          | b                | a-b                        
:--------- | :--------------- | :--------------------------
2022-01-01 | 10:00:00.0000000 | 2022-01-01T10:00:00.0000000
2022-01-01 | null             | a-null                     
null       | 10:00:00.0000000 | null-b                     
null       | null             | null-null

db<>fiddle here

如果两列都不是 NULL，我如何获得 SQL 'When' 子句以仅 return concat 数据？

how do I get a SQL 'When' clause to only return concat data if both columns are NOT NULL?

sql-server