一种效率比较高的分页存储过程

Posted 2020-09-02 雪原日暮

CREATE PROCEDURE pagination3

@tblName   varchar(255),       -- 表名

@strGetFields varchar(1000) = ‘*‘,  -- 需要返回的列 

@fldName varchar(255)=‘‘,      -- 排序的字段名

@PageSize   int = 10,          -- 页尺寸

@PageIndex  int = 1,           -- 页码

@doCount  bit = 0,   -- 返回记录总数, 非 0 值则返回

@OrderType bit = 0,  -- 设置排序类型, 非 0 值则降序

@strWhere  varchar(1500) = ‘‘  -- 查询条件 (注意: 不要加 where)

AS

declare @strSQL   varchar(5000)       -- 主语句

declare @strTmp   varchar(110)        -- 临时变量

declare @strOrder varchar(400)        -- 排序类型

 

if @doCount != 0

  begin

    if @strWhere !=‘‘

    set @strSQL = "select count(*) as Total from [" + @tblName + "] where "+@strWhere

    else

    set @strSQL = "select count(*) as Total from [" + @tblName + "]"

end  

--以上代码的意思是如果@doCount传递过来的不是0，就执行总数统计。以下的所有代码都是@doCount为0的情况

else

begin

 

if @OrderType != 0

begin

    set @strTmp = "<(select min"

set @strOrder = " order by [" + @fldName +"] desc"

--如果@OrderType不是0，就执行降序，这句很重要！

end

else

begin

    set @strTmp = ">(select max"

    set @strOrder = " order by [" + @fldName +"] asc"

end

 

if @PageIndex = 1

begin

    if @strWhere != ‘‘   

    set @strSQL = "select top " + str(@PageSize) +" "+@strGetFields+ "  from [" + @tblName + "] where " + @strWhere + " " + @strOrder

     else

     set @strSQL = "select top " + str(@PageSize) +" "+@strGetFields+ "  from ["+ @tblName + "] "+ @strOrder

--如果是第一页就执行以上代码，这样会加快执行速度

end

else

begin

--以下代码赋予了@strSQL以真正执行的SQL代码

set @strSQL = "select top " + str(@PageSize) +" "+@strGetFields+ "  from ["

    + @tblName + "] where [" + @fldName + "]" + @strTmp + "(["+ @fldName + "]) from (select top " + str((@PageIndex-1)*@PageSize) + " ["+ @fldName + "] from [" + @tblName + "]" + @strOrder + ") as tblTmp)"+ @strOrder

 

if @strWhere != ‘‘

    set @strSQL = "select top " + str(@PageSize) +" "+@strGetFields+ "  from ["

        + @tblName + "] where [" + @fldName + "]" + @strTmp + "(["

        + @fldName + "]) from (select top " + str((@PageIndex-1)*@PageSize) + " ["

        + @fldName + "] from [" + @tblName + "] where " + @strWhere + " "

        + @strOrder + ") as tblTmp) and " + @strWhere + " " + @strOrder

end 

end   

exec (@strSQL)

GO