IF OBJECT_ID('T') IS NOT NULL
    DROP TABLE T
CREATE TABLE T(ID INT, ParentID INT, LEVEL INT,OrderNum int)
--测试数据
INSERT INTO T
SELECT 960, 878, 1, 2 UNION ALL
SELECT 961, 960, 2 ,3 UNION ALL
SELECT 962, 961, 3 ,4 UNION ALL
SELECT 963, 878, 1 ,7 UNION ALL
SELECT 964, 963, 2 ,8 UNION ALL
SELECT 965, 964, 3 ,9 UNION ALL
SELECT 966, 963, 2 ,11 UNION ALL
SELECT 967, 878, 1 ,13 UNION ALL
SELECT 968, 878, 1 ,14 UNION ALL
SELECT 969, 878, 1 ,15 

CREATE PROC sp_getUser
(
    @level INT ,--每页几个用户
    @PageIndex int--页面索引
)
AS 
BEGIN

 DECLARE @_tab TABLE (id INT IDENTITY(1,1),startIndex INT, endIndex INT,userID INT)
 DECLARE @_startIndex INT
 DECLARE @_endIndex INT
 
 ;WITH cte AS 
 (
    SELECT  [主ID]=ID, * 
    FROM T 
    WHERE [LEVEL]=1
    
    UNION ALL
    SELECT [主ID]=c.[主ID],a.* FROM T a JOIN cte c ON a.ParentID =c.Id
    
 )
  INSERT INTO  @_tab
  SELECT MIN(id),MAX(id),[主ID] FROM cte GROUP BY [主ID] -- ORDER BY OrderNum
  --每页的开始索引
  SELECT @_startIndex=startIndex 
  FROM  
  (
    SELECT *
    FROM  @_tab
    WHERE id BETWEEN @level*@PageIndex-1 AND @level*@PageIndex
  ) AS t
  WHERE t.id=@level*@PageIndex-1
  --每页的结束索引
  SELECT @_endIndex=endIndex
  FROM  
  (
    SELECT *
    FROM  @_tab
    WHERE id BETWEEN @level*@PageIndex-1  AND @level*@PageIndex
  ) AS t
  WHERE t.id=@level*@PageIndex
  
  PRINT 'start:'+ CAST(@_startIndex AS VARCHAR )
  PRINT 'end:'+CAST(@_endIndex AS VARCHAR )
  
  IF @_endIndex IS NULL OR LEN(@_endIndex)=0
  BEGIN
      SELECT * FROM T WHERE  id >=@_startIndex
  END
  ELSE
  BEGIN
      SELECT * FROM T WHERE id BETWEEN @_startIndex AND @_endIndex
  END
  
  
END
--每页2个用户,第一页
EXEC sp_getUser 2,1
/*
ID          ParentID    LEVEL       OrderNum
----------- ----------- ----------- -----------
960         878         1           2
961         960         2           3
962         961         3           4
963         878         1           7
964         963         2           8
965         964         3           9
966         963         2           11

(7 行受影响)
*/
--每页2个用户,第二页
EXEC sp_getUser 2,2
/*
ID          ParentID    LEVEL       OrderNum
----------- ----------- ----------- -----------
967         878         1           13
968         878         1           14

(2 行受影响)
*/
--每页2个用户,第三页
EXEC sp_getUser 2,3
/*
ID          ParentID    LEVEL       OrderNum
----------- ----------- ----------- -----------
969         878         1           15

(1 行受影响)

*/