SQL 根据分类表实现的分页存储过程

--要分页的原始数据
CREATE TABLE tb(
ID    int PRIMARY KEY,  --记录编号
grade  varchar(10),     --类别名称
uptime datetime)        --更新时间
INSERT tb SELECT 1 ,'a','2004-12-11'
UNION ALL SELECT 2 ,'b','2004-12-11'
UNION ALL SELECT 3 ,'c','2004-12-11'
UNION ALL SELECT 4 ,'a','2004-12-12'
UNION ALL SELECT 5 ,'c','2004-12-13'
UNION ALL SELECT 6 ,'c','2004-12-13'
UNION ALL SELECT 7 ,'a','2004-12-14'
UNION ALL SELECT 8 ,'a','2004-12-15'
UNION ALL SELECT 9 ,'b','2004-12-16'
UNION ALL SELECT 10,'b','2004-12-17'
UNION ALL SELECT 11,'a','2004-12-17'

--分页定义表
CREATE TABLE tb_Page(
grade   varchar(10) PRIMARY KEY, --类别名称,与tb表的grade关联
Records int,                     --每页显示的记录数
Orders  int)                     --在页中的显示顺序
INSERT tb_Page SELECT 'c',2,1
UNION  ALL     SELECT 'b',1,2
UNION  ALL     SELECT 'a',2,3
GO

--实现分页处理的存储过程
CREATE PROC p_PageView
@PageCurrent int=1  --要显示的当前页码
AS
SET NOCOUNT ON
--得到每页的记录数
DECLARE @PageSize int
SELECT @PageSize=SUM(Records) FROM tb_Page
IF ISNULL(@PageSize,0)<0 RETURN

--分页显示处理
SET @PageCurrent=@PageCurrent*@PageSize
SET ROWCOUNT @PageCurrent
SELECT SID=IDENTITY(int,1,1),ID
INTO # FROM(
SELECT TOP 100 PERCENT a.ID
FROM tb a
LEFT JOIN tb_Page b ON a.grade=b.grade
ORDER BY CASE WHEN b.grade IS NULL THEN 1 ELSE 0 END,--分类没有定义的显示在最后
((SELECT COUNT(*) FROM tb
WHERE grade=a.grade
AND (uptime>a.uptime OR uptime=a.uptime AND id>=a.id))-1)
/b.Records,
b.Orders,a.ID DESC)a
IF @PageCurrent>@PageSize
BEGIN
SET @PageCurrent=@PageCurrent-@PageSize
SET ROWCOUNT @PageCurrent
DELETE FROM #
END
SELECT a.* FROM tb a,# b
WHERE a.ID=b.ID
ORDER BY b.SID
GO

--调用
EXEC p_PageView 2
/*--结果
ID          grade      uptime
----------- ---------- ------------------------------------------------------
3           c          2004-12-11 00:00:00.000
9           b          2004-12-16 00:00:00.000
7           a          2004-12-14 00:00:00.000
4           a          2004-12-12 00:00:00.000
2           b          2004-12-11 00:00:00.000
--*/