TSQL-让它变得更好

-- Very Narrow (all IDs are passed in)
IF(@EmpID IS NOT NULL AND @DeptID IS NOT NULL AND @CityID IS NOT NULL)
   BEGIN    
      SELECT
         e.EmpName 
         ,d.DeptName
         ,c.CityName
      FROM
         Employee e WITH (NOLOCK)
         JOIN Department d WITH (NOLOCK) ON e.deptid = d.deptid
         JOIN City c WITH (NOLOCK) ON e.CityID = c.CityID
      WHERE 
         e.EmpID = @EmpID
   END
-- Just 2 IDs passed in
ELSE IF(@DeptID IS NOT NULL AND @CityID IS NOT NULL)
   BEGIN
      SELECT
         e.EmpName 
         ,d.DeptName
         ,NULL AS [CityName]
      FROM
         Employee e WITH (NOLOCK)
         JOIN Department d WITH (NOLOCK) ON e.deptid = d.deptid
         JOIN City c WITH (NOLOCK) ON e.CityID = c.CityID
      WHERE 
         d.deptID = @DeptID
   END
-- Very Broad (just 1 ID passed in)
ELSE IF(@CityID IS NOT NULL)
   BEGIN
      SELECT
         e.EmpName 
         ,NULL AS [DeptName]
         ,NULL AS [CityName]
      FROM
         Employee e WITH (NOLOCK)
         JOIN Department d WITH (NOLOCK) ON e.deptid = d.deptid
         JOIN City c WITH (NOLOCK) ON e.CityID = c.CityID
      WHERE 
         c.CityID = @CityID
   END
-- None (Nothing passed in)
ELSE 
   BEGIN
      SELECT
         NULL AS [EmpName]
         ,NULL AS [DeptName]
         ,NULL AS [CityName]
   END

问题:有没有更好的方法(或者具体来说,我可以做任何事情没有如果…其他条件)?