where语句中多条件查询字段NULL与NOT NULL不确定性查询

SELECT　* FROM Table
where a.TenantKey=@TenantId 
AND (@ProjectKeys is null or b.RecuritProjectKey in (select * from dbo.f_SplitToInt(@ProjectKeys,',')))
AND (@ProjectDutyUserKeys is null or b.ProjectDutyUserKey in (select * from dbo.f_SplitToInt(@ProjectDutyUserKeys,',')))

当@ProjectKeys&@ProjectDutyUserKeys两个参数有值无值都不会影响查询，省去了IF……ELSE……