Discuz!NT 代码阅读笔记(8.1)--DNT的几个分页存储过程解析
(3) dnt_getfavoriteslistbyalbum 获取用户收藏列表并分页
CREATE PROCEDURE [dnt_getfavoriteslistbyalbum]
@uid INT ,
@pagesize INT ,
@pageindex INT
AS
DECLARE @strSQL VARCHAR(5000)
--下边这个语句找出所有用户收藏，临时记录在@strSQL中
SET @strSQL = 'SELECT [f].[tid], [f].[uid], [albumid], [albumcateid], [userid] AS [posterid], [username] AS [poster], [title], [description], [logo], [password], [imgcount], [views], [type], [createdatetime] AS [postdatetime] FROM [dnt_favorites] [f],[dnt_albums] [albums] WHERE [f].[tid]=[albums].[albumid] AND [f].[typeid]=1 AND [f].[uid]='
+ STR(@uid)
IF @pageindex = 1
BEGIN --第一页的处理，简单的SELECT TOP
SET @strSQL = 'SELECT TOP ' + STR(@pagesize)
+ ' [tid], [uid], [albumid], [albumcateid], [posterid], [poster], [title], [description], [logo], [password], [imgcount], [views], [type], [postdatetime] FROM ('
+ @strSQL + ') f' + ' ORDER BY [tid] DESC'
END
ELSE
BEGIN --其他页的处理，跟第1种的处理相似 也是选出( @pageindex - 1 ) * @pagesize个数据，逆序排列后返回前@pagesize个数据
SET @strSQL = 'SELECT TOP ' + STR(@pagesize)
+ ' [tid], [uid], [albumid], [albumcateid], [posterid], [poster], [title], [description], [logo], [password], [imgcount], [views], [type], [postdatetime] FROM ('
+ @strSQL
+ ') f1 WHERE [tid] < (SELECT MIN([tid]) FROM (SELECT TOP '
+ STR(( @pageindex - 1 ) * @pagesize) + ' [tid] FROM ('
+ @strSQL + ') f2' + ' ORDER BY [tid] DESC) AS tblTmp)'
+ ' ORDER BY [tid] DESC'
END
EXEC(@strSQL) --组织完SQL语句，执行以下就OK了
GO BEGIN
SET @strSQL = 'SELECT TOP ' + STR(@pagesize)
+ ' [tid], [uid], [albumid], [albumcateid], [posterid], [poster], [title], [description], [logo], [password], [imgcount], [views], [type], [postdatetime] FROM ('
+ @strSQL
+ ') f1 WHERE [tid] < (SELECT MIN([tid]) FROM (SELECT TOP '
+ STR(( @pageindex - 1 ) * @pagesize) + ' [tid] FROM ('
+ @strSQL + ') f2' + ' ORDER BY [tid] DESC) AS tblTmp)'
+ ' ORDER BY [tid] DESC'
END
EXEC(@strSQL)
GO
(4) dnt_getattentiontopics 分页获取需要被关注的主题列表
CREATE PROCEDURE [dnt_getattentiontopics] --分页获取需要被关注的主题列表
@fid VARCHAR(255) = '' ,
@tpp INT , --每页显示数量
@pageid INT , --页码
@condition NVARCHAR(255) = '' --搜索条件
AS
DECLARE @pagetop INT ,
@strSQL VARCHAR(5000)
SET @pagetop = ( @pageid - 1 ) * @tpp
IF @pageid = 1
BEGIN
SET @strSQL = 'SELECT TOP ' + STR(@tpp)
+ ' * FROM [dnt_topics] WHERE [displayorder]>=0 AND [attention]=1'
IF @fid <> '0'
SELECT @strSQL = @strSQL + ' AND [fid] IN (' + @fid + ')'
IF @condition <> ''
SELECT @strSQL = @strSQL + @condition
SELECT @strSQL = @strSQL + ' ORDER BY [lastpost] DESC'
END
ELSE
BEGIN
SET @strSQL = 'SELECT TOP ' + STR(@tpp)
+ ' * FROM [dnt_topics] WHERE [tid] < (SELECT MIN([tid]) FROM (SELECT TOP ' --也是选择出来顶上的( 页码 - 1 ) * 每页数量个行
+ STR(@pagetop)
+ ' [tid] FROM [dnt_topics] WHERE [displayorder]>=0 AND [attention]=1'
IF @fid <> '0' --加入搜索条件
SELECT @strSQL = @strSQL + ' AND [fid] IN (' + @fid + ')'
IF @condition <> ''
SELECT @strSQL = @strSQL + @condition
SELECT @strSQL = @strSQL + ' ORDER BY [tid] DESC'
SELECT @strSQL = @strSQL + ' ) AS T) '
IF @fid <> '0'
SELECT @strSQL = @strSQL + ' AND [fid] IN (' + @fid + ')'
IF @condition <> ''
SELECT @strSQL = @strSQL + @condition
SELECT @strSQL = @strSQL
+ ' AND [displayorder]>=0 AND [attention]=1 ORDER BY [tid] DESC'
END
EXEC(@strSQL)
GO