分页存储过程（转）

CREATE PROC
sp_PageView
@tbname     sysname,               —要分页显示的表名

@FieldKey   nvarchar(1000),      —用于定位记录的主键(惟一键)字段,可以是逗号分隔的多个字段

@PageCurrent int=1,               —要显示的页码

@PageSize   int=10,                —每页的大小(记录数)

@FieldShow nvarchar(1000)=”,      —以逗号分隔的要显示的字段列表,如果不指定,则显示所有字段

@FieldOrder nvarchar(1000)=”,      —以逗号分隔的排序字段列表,可以指定在字段后面指定DESC/ASC

                                          用于指定排序顺序
@Where    nvarchar(1000)=”,     —查询条件

@PageCount int OUTPUT             —总页数

AS

SET NOCOUNT ON

—检查对象是否有效

IF OBJECT_ID(@tbname) IS NULL

BEGIN


RAISERROR(N‘对象”%s”不存在‘,1,16,@tbname
)
    RETURN

END

IF OBJECTPROPERTY(OBJECT_ID(@tbname),N‘IsTable‘)=0


AND OBJECTPROPERTY(OBJECT_ID(@tbname),N‘IsView‘)=0


AND OBJECTPROPERTY(OBJECT_ID(@tbname),N‘IsTableFunction‘)=0

BEGIN


RAISERROR(N‘“%s”不是表、视图或者表值函数‘,1,16,@tbname
)
    RETURN

END

—分页字段检查

IF ISNULL(@FieldKey,N”)=”

BEGIN

RAISERROR(N‘分页处理需要主键（或者惟一键）‘,1,16
)
RETURN

END

—其他参数检查及规范

IF ISNULL(@PageCurrent,0)<1 SET @PageCurrent=1

IF ISNULL(@PageSize,0)<1 SET @PageSize=10

IF ISNULL(@FieldShow,N”)=N” SET @FieldShow=N‘*‘

IF ISNULL(@FieldOrder,N”)=N”


SET @FieldOrder=N”

ELSE


SET @FieldOrder=N‘ORDER BY ‘+LTRIM(@FieldOrder
)
IF ISNULL(@Where,N”)=N”


SET @Where=N”

ELSE


SET @Where=N‘WHERE (‘+@Where+N‘)‘

—如果@PageCount为NULL值,则计算总页数(这样设计可以只在第一次计算总页数,以后调用时,把总页数传回给存储过程,避免再次计算总页数,对于不想计算总页数的处理而言,可以给@PageCount赋值)

IF @PageCount IS NULL

BEGIN


DECLARE @sql nvarchar(4000
)
    SET @sql=N‘SELECT @PageCount=COUNT(*)‘


+N‘ FROM ‘+@tbname


+N‘ ‘+@Where


EXEC sp_executesql @sql,N‘@PageCount int OUTPUT‘,@PageCount
OUTPUT
    SET @PageCount=(@PageCount+@PageSize–1)/@PageSize

END

—计算分页显示的TOPN值

DECLARE @TopN varchar(20),@TopN1 varchar(20
)
SELECT @TopN=@PageSize
,
@TopN1=(@PageCurrent–1)*@PageSize

—第一页直接显示

IF @PageCurrent=1


EXEC(N‘SELECT TOP ‘+@TopN


+N‘ ‘+@FieldShow


+N‘ FROM ‘+@tbname


+N‘ ‘+@Where


+N‘ ‘+@FieldOrder
)
ELSE

BEGIN


—处理别名

    IF @FieldShow=N‘*‘


SET @FieldShow=N‘a.*‘

—生成主键(惟一键)处理条件

    DECLARE @Where1 nvarchar(4000),@Where2 nvarchar(4000
),
        @s nvarchar(1000),@Field
sysname
    SELECT @Where1=N”,@Where2=N”,@s=@FieldKey


WHILE CHARINDEX(N‘,‘,@s)>0


SELECT @Field=LEFT(@s,CHARINDEX(N‘,‘,@s)–1
),
            @s=STUFF(@s,1,CHARINDEX(N‘,‘,@s),N”
),
            @Where1=@Where1+N‘ AND a.‘+@Field+N‘=b.‘+@Field
,
            @Where2=@Where2+N‘ AND b.‘+@Field+N‘ IS NULL‘
,
            @Where=REPLACE(@Where,@Field,N‘a.‘+@Field
),
            @FieldOrder=REPLACE(@FieldOrder,@Field,N‘a.‘+@Field
),
            @FieldShow=REPLACE(@FieldShow,@Field,N‘a.‘+@Field
)
    SELECT @Where=REPLACE(@Where,@s,N‘a.‘+@s
),
        @FieldOrder=REPLACE(@FieldOrder,@s,N‘a.‘+@s
),
        @FieldShow=REPLACE(@FieldShow,@s,N‘a.‘+@s
),
        @Where1=STUFF(@Where1+N‘ AND a.‘+@s+N‘=b.‘+@s,1,5,N”
),
        @Where2=CASE


WHEN @Where=” THEN N‘WHERE (‘


ELSE @Where+N‘ AND (‘


END+N‘b.‘+@s+N‘ IS NULL‘+@Where2+N‘)‘

—执行查询

    EXEC(N‘SELECT TOP ‘+@TopN


+N‘ ‘+@FieldShow


+N‘ FROM ‘+@tbname


+N‘ a LEFT JOIN(SELECT TOP ‘+@TopN1


+N‘ ‘+@FieldKey


+N‘ FROM ‘+@tbname


+N‘ a ‘+@Where


+N‘ ‘+@FieldOrder


+N‘)b ON ‘+@Where1


+N‘ ‘+@Where2


+N‘ ‘+@FieldOrder
)
END