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分页存储过程,综合了NOT_IN和SET ROWcount

2024-07-21 02:05:44
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分页存储过程,自己把“not_in”和“set rowcount”两种方式综合了一下。
“set rowcount”算法不变,“not_in”排序时加了主键字段,这样速度提升了很多而且结果是单向唯一的,但不是双向可逆的。“set rowcount”没有速度问题,“not_in”排序加了主键字段后在30w记录时对非索引字段、非聚合字段的排序翻一页不过3秒钟,还可以吧:p
----------------------
create    procedure paging_custom
(
@tables varchar(1000),
@pk varchar(100),
@sort varchar(200) = null,
@isascending bit=1,
@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 @sort type*/
declare @strfilter varchar(1000)
declare @strsimplefilter varchar(1000)
declare @strgroup varchar(1000)

declare @sorttable varchar(100)
declare @sortname varchar(100)
declare @strpkcolumn varchar(200)
declare @strsortcolumn varchar(200)
declare @operator char(2)

/*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
begin
 set @strgroup = ' '
end

/*count*/
exec('select count(*) from ' [email protected]+' '+ @strfilter)

/*set sorting variables.*/
set @strsortcolumn [email protected]

/*operator and asc_desc*/
declare @strasc_des varchar(10)
if @isascending = 0
 begin
  
  set @operator = '<='
  set @strasc_des = ' desc '
 end
else
 begin
  set @operator = '>='
  set @strasc_des = ' asc '
 end
if charindex('.', @pk) > 0
 begin
  set @strpkcolumn = substring(@pk, 0, charindex('.',@pk))  
 end
else
 begin
  set @strpkcolumn = @pk  
 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

/*handler complex table*/
--be join table,so get the left table
if charindex(' join ',@tables) > 0
begin
set @sorttable=substring(ltrim(@tables),0,charindex(' ',@tables))
set @strsortcolumn = @sorttable+'.'[email protected]
end


/*check the sortcolumn if be unique*/
declare @tempname varchar(100)
if @sortname <> @strpkcolumn
begin
select @tempname=b.name
from sysobjects a inner join
      sysobjects b on a.id = b.parent_obj
    inner join sysindexes c on b.name = c.name inner join
      sysindexkeys d on c.id = d.id and c.indid = d.indid inner join
      syscolumns e on d.id = e.id and d.colid = e.colid
where (b.xtype = 'uq') and (a.name = @sorttable) and (e.name = @sortname)

if @tempname is null goto:paging_not_in
end

declare @type varchar(100)
declare @prec int

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

/*the left table doesn't contain sortcolumn */
--if  @type is null or @type=''  goto:paging_not_in

if charindex('char', @type) > 0
   set @type = @type + '(' + cast(@prec as varchar) + ')'

declare @strpagesize varchar(50)
declare @strstartrow varchar(50)


/*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))
 
/*execute dynamic query*/ 

exec( 'declare @sortcolumn ' + @type + '
set rowcount ' + @strstartrow +
 'select @sortcolumn=' + @strsortcolumn + ' from ' + @tables + @strfilter + ' ' + @strgroup +
 ' order by ' + @sort + @strasc_des+'set rowcount ' + @strpagesize +
 'select ' + @fields + ' from ' + @tables + ' where ' + @strsortcolumn + @operator + ' @sortcolumn ' +
 @strsimplefilter + ' ' + @strgroup + ' order by ' + @sort + @strasc_des
)
return

paging_not_in:
--declare @strpagesize varchar(50)
--set @strpagesize = cast(@pagesize as varchar(50))
declare @strtotalnum int
set @strtotalnum = (@pagenumber - 1)*@pagesize
--第一页
--declare @strsql varchar(8000)
if  @strtotalnum = 0
begin
exec('select top '[email protected]+' '[email protected]+' from '[email protected]+' '[email protected]+ @strgroup + ' order by ' + @sort + @strasc_des)  
end
else
begin
 exec('select top '[email protected]+' '[email protected]+' from '[email protected]+'  where '
[email protected]+' not in(select top '
[email protected]+' '[email protected]+' from '[email protected]+' '[email protected]+ @strgroup +
 ' order by ' + @sort + @strasc_des
+') '[email protected]+ @strgroup + ' order by ' + @sort + @strasc_des)
end

go
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