精彩的近乎完美的分页存储过程_MySQL

CREATE procedure main_table_pwqzc
(@pagesize int,
@pageindex int,
@docount bit,
@this_id)
as
if(@docount=1)
begin
select count(id) from luntan where this_id=@this_id
end
else
begin
declare @indextable table(id int identity(1,1),nid int)
declare @PageLowerBound int
declare @PageUpperBound int
set @PageLowerBound=(@pageindex-1)*@pagesize
set @PageUpperBound=@PageLowerBound @pagesize
set rowcount @PageUpperBound
insert into @indextable(nid) select id from luntan where this_id=@this_id order by reply_time desc
select a.* from luntan a,@indextable t where a.id=t.nid
and t.id>@PageLowerBound and t.id<=@PageUpperBound order by t.id
end
GO

存储过程会根据传入的参数@docount来确定是不是要返回所有要分页的记录总数
特别是这两行
set rowcount @PageUpperBound
insert into @indextable(nid) select id from luntan where this_id=@this_id order by reply_time desc

真的是妙不可言!!set rowcount @PageUpperBound当记录数达到@PageUpperBound时就会停止处理查询
,select id 只把id列取出放到临时表里,select a.* from luntan a,@indextable t where a.id=t.nid
and t.id>@PageLowerBound and t.id<=@PageUpperBound order by t.id
而这句也只从表中取出所需要的记录,而不是所有的记录,结合起来,极大的提高了效率!!
妙啊,真的妙!!!!

CREATE PROCEDURE Paging_RowCount
(
@Tables varchar(1000),
@PK varchar(100),
@Sort varchar(200) = NULL,
@PageNumber int = 1,
@PageSize int = 10,
@Fields varchar(1000) = '*',
@Filter varchar(1000) = NULL,
@Group varchar(1000) = NULL)
AS

/*Default Sorting*/
IF @Sort IS NULL OR @Sort = ''
SET @Sort = @PK

/*Find the @PK type*/
DECLARE @SortTable varchar(100)
DECLARE @SortName varchar(100)
DECLARE @strSortColumn varchar(200)
DECLARE @operator char(2)
DECLARE @type varchar(100)
DECLARE @prec int

/*Set sorting variables.*/
IF CHARINDEX('DESC',@Sort)>0
BEGIN
SET @strSortColumn = REPLACE(@Sort, 'DESC', '')
SET @operator = '<='
END
ELSE
BEGIN
IF CHARINDEX('ASC', @Sort) = 0
SET @strSortColumn = REPLACE(@Sort, 'ASC', '')
SET @operator = '>='
END

IF CHARINDEX('.', @strSortColumn) > 0
BEGIN
SET @SortTable = SUBSTRING(@strSortColumn, 0, CHARINDEX('.',@strSortColumn))
SET @SortName = SUBSTRING(@strSortColumn, CHARINDEX('.',@strSortColumn) 1, LEN(@strSortColumn))
END
ELSE
BEGIN
SET @SortTable = @Tables
SET @SortName = @strSortColumn
END

SELECT @type=t.name, @prec=c.prec
FROM sysobjects o
JOIN syscolumns c on o.id=c.id
JOIN systypes t on c.xusertype=t.xusertype
WHERE o.name = @SortTable AND c.name = @SortName

IF CHARINDEX('char', @type) > 0
SET @type = @type '(' CAST(@prec AS varchar) ')'

DECLARE @strPageSize varchar(50)
DECLARE @strStartRow varchar(50)
DECLARE @strFilter varchar(1000)
DECLARE @strSimpleFilter varchar(1000)
DECLARE @strGroup varchar(1000)

/*Default Page Number*/
IF @PageNumber < 1
SET @PageNumber = 1

/*Set paging variables.*/
SET @strPageSize = CAST(@PageSize AS varchar(50))
SET @strStartRow = CAST(((@PageNumber - 1)*@PageSize 1) AS varchar(50))

/*Set filter & group variables.*/
IF @Filter IS NOT NULL AND @Filter != ''
BEGIN
SET @strFilter = ' WHERE ' @Filter ' '
SET @strSimpleFilter = ' AND ' @Filter ' '
END
ELSE
BEGIN
SET @strSimpleFilter = ''
SET @strFilter = ''
END
IF @Group IS NOT NULL AND @Group != ''
SET @strGroup = ' GROUP BY ' @Group ' '
ELSE
SET @strGroup = ''

/*Execute dynamic query*/
EXEC(
'
DECLARE @SortColumn ' @type '
SET ROWCOUNT ' @strStartRow '
SELECT @SortColumn=' @strSortColumn ' FROM ' @Tables @strFilter ' ' @strGroup ' ORDER BY ' @Sort '
SET ROWCOUNT ' @strPageSize '
SELECT ' @Fields ' FROM ' @Tables ' WHERE ' @strSortColumn @operator ' @SortColumn ' @strSimpleFilter ' ' @strGroup ' ORDER BY ' @Sort '
'
)
GO

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