如何处理这样的一个存储过程？（SiteID如果值为空，那么a.SiteName就不出现；

[lilinew]

如何处理这样的一个存储过程？（select a,b from **）
CREATE PROCEDURE XGetCluster
AS
SET NOCOUNT ON


select a.ScopeName, b.CurrentLoad As CurrentLoad,c.ConnectionCount As Con
nectionCount,a.MasterDispatcher As MasterDispatcher,a.SiteID As SiteID,a.SiteN
ame from XNetCluster As a,
XNetServer As b ,XNetRunTable As c where a.ScopeID = b.ScopeID AND a.SiteID
=c.SiteID

首先说明该存储过程需要改进为以下的形式
这里SiteID如果值为空，那么a.SiteName就不出现；
SiteID如果值不为空，那么a.SiteName就出现SiteID就不出现；

请教如何写嵌套判断语句

[愉快的登山者]

CREATE PROCEDURE XGetCluster
AS
SET NOCOUNT ON


select a.ScopeName, b.CurrentLoad As CurrentLoad,c.ConnectionCount As Con
nectionCount,a.MasterDispatcher As MasterDispatcher,(case when a.SiteID is not null then a.SiteName else null end ) As SiteID,a.SiteN
ame from XNetCluster As a,
XNetServer As b ,XNetRunTable As c where a.ScopeID = b.ScopeID AND a.SiteID
=c.SiteID


愉快的登山者

⊙
◢◣◢◣◢◣