Sql server B为空时排除A列的记录

需要有关查询的帮助，该查询将允许我在列a中排除一条记录（如果列中存在一条记录，且该记录的值为null）

假设我有两行是A列名为“test”，它们的B列值分别为1和null。下面是我正在处理的一个查询，在我的场景中，对象ID是a列，endversion是B列

select b.PortID, 
       max(endversion)as EndVersion, 
       d.ShortName as RuleName 
from xr.ObjectPropertyValue a 
       join moxyportfolio b on a.objectid=b.portkey 
       join xr.AssignAllObjectsRule c on a.Objectclassid=c.ObjectClassID -- can replace with xr.assignobjectrule if it's rule is not assigned to all portfolios.
       join xr.rulebase d on c.RuleID=d.RuleID 
where objectid in (select objectid from xr.objectpropertyvalue where endversion is not null) 
group by a.ObjectId, b.portid,d.ShortName

---

您可以使用

have

：

select 
    b.PortID,
    max(endversion) as EndVersion,
    d.ShortName as RuleName 
from xr.ObjectPropertyValue a 
join moxyportfolio b 
    on a.objectid = b.portkey 
join xr.AssignAllObjectsRule c 
    on a.Objectclassid = c.ObjectClassID -- can replace with xr.assignobjectrule if it's rule is not assigned to all portfolios.
join xr.rulebase d 
    on c.RuleID = d.RuleID 
group by a.ObjectId, b.portid, d.ShortName
having sum(case when endversion is null then 1 else 0 end) = 0

---

仅当列B不为空时才为列A选择值（否则为空）：

仅当列B不为null（否则为null）时，才为列a选择一个值：

---

endversion列是否来自xr.ObjectPropertyValue表？

 SELECT COLA
 FROM TABLE
 WHERE COLB IS NOT NULL

 SELECT CASE WHEN COLB IS NOT NULL THEN COLA ELSE NULL END AS COLA
 FROM TABLE