select a,count(b) from tb group by a order by count(b) ?
SQL Server高性能分页存储过程
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 ENDSELECT @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 = @SortNameIF 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
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
ENDSELECT @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 = @SortNameIF 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