一个解决方案是对整个语句进行子选择,将where子句应用于其结果
select *
from (
select cast(de.ApprovalOrder AS VARCHAR(32))
+ cast(de.EntityCode AS VARCHAR(32))
+ isnull(cast(de.DelegationCode AS VARCHAR(32)), '') as 'RowID'
, *
from workflow.delegation_engine de
) de
where de.RowID IS NOT NULL
另一种解决方案是在WHERE子句中重复整个条件语句
select cast(de.ApprovalOrder AS VARCHAR(32))
+ cast(de.EntityCode AS VARCHAR(32))
+ isnull(cast(de.DelegationCode AS VARCHAR(32)), '') as 'RowID' ,
*
from workflow.delegation_engine de
where cast(de.ApprovalOrder AS VARCHAR(32))
+ cast(de.EntityCode AS VARCHAR(32))
+ isnull(cast(de.DelegationCode AS VARCHAR(32)), '') IS NOT NULL
或者你可以测试每个单独的字段是否为NULL。
select cast(de.ApprovalOrder AS VARCHAR(32))
+ cast(de.EntityCode AS VARCHAR(32))
+ isnull(cast(de.DelegationCode AS VARCHAR(32)), '') as 'RowID' ,
*
from workflow.delegation_engine de
where de.ApprovalOrder IS NOT NULL
AND de.EntityCode IS NOT NULL
<> NULL
会给操作者带来问题。我认为这不是预期的条件子句。 - user596075