116.排行榜处理-案例

落日映苍穹つ 2024-02-19 19:02 8阅读 0赞

--图书销售数据表
    CREATE TABLE tb(
    Books nvarchar(30), --书名
    Date datetime,     --销售日期
    Sales int)         --销售数量
    --生成测试数据
    INSERT tb SELECT 
    	CHAR(65+RAND(CHECKSUM(NEWID()))*25),
    	DATEADD(Day,1-RAND(CHECKSUM(NEWID()))*500,GETDATE()),
    	RAND(CHECKSUM(NEWID()))*360
    FROM sysobjects a,sysobjects b
    --显示数据
    SELECT * FROM tb
    GO
    
    --排行榜处理的存储过程
    CREATE PROC p_Qry
    @Type  nchar(1)=N'日',  --排行榜处理类型(日、周、月、季、年)
    @Date  datetime=null,   --排行榜日期,不指定为当前日期
    @TopN int=10          --记录数
    AS
    SET NOCOUNT ON
    DECLARE @p_dt_begin datetime,@dt_begin datetime
    
    --参数检测
    IF CHARINDEX(@Type,N'日周月季年')=0
    	SET @Type=N'日'
    IF @Date IS NULL
    	SET @Date=CONVERT(char(10),GETDATE(),120)
    ELSE
    	SET @Date=CONVERT(char(10),@Date,120)
    IF ISNULL(@TopN,0)<1
    	SET @TopN=10
    
    --根据@Type决定计算的起始日期
    IF @Type=N'日'
    	SELECT
    		@dt_begin=@Date,
    		@Date=DATEADD(Day,1,@Date),
    		@p_dt_begin=DATEADD(Day,-1,@dt_begin)
    ELSE IF @Type=N'周'
    	SELECT 
    		@dt_begin=DATEADD(Day,-(DATEPART(Weekday,@Date)+@@DATEFIRST-2)%7,@Date),
    		@Date=DATEADD(Day,7,@dt_begin),
    		@p_dt_begin=DATEADD(Day,-7,@dt_begin)
    ELSE IF @Type=N'月'
    	SELECT 
    		@dt_begin=CONVERT(char(8),@Date,120)+'01',
    		@Date=DATEADD(Month,1,@dt_begin),
    		@p_dt_begin=DATEADD(Month,-1,@dt_begin)
    ELSE IF @Type=N'季'
    	SELECT 
    		@dt_begin=CONVERT(char(8),
    			DATEADD(Month,DATEPART(Quarter,@Date)*3-Month(@Date)-2,@Date),
    			120)+'1',
    		@Date=DATEADD(Month,3,@dt_begin),
    		@p_dt_begin=DATEADD(Month,-3,@dt_begin)
    ELSE
    	SELECT 
    		@dt_begin=CONVERT(char(5),@Date,120)+'01-01',
    		@Date=DATEADD(Year,1,@dt_begin),
    		@p_dt_begin=DATEADD(Year,-1,@dt_begin)
    
    --取排名数据到临时表
    SET ROWCOUNT @TopN
    --最新名称
    SELECT Books,Sales_Amount=SUM(Sales)
    INTO #1 FROM tb
    WHERE Date>=@dt_begin AND Date<@Date
    GROUP BY Books
    ORDER BY Sales_Amount DESC
    --上期名次
    SELECT Books,Sales_Amount=SUM(Sales) 
    INTO #2 FROM tb
    WHERE Date>=@p_dt_begin AND Date<@dt_begin
    GROUP BY Books
    ORDER BY Sales_Amount DESC
    
    --显示结果
    SELECT a.Books,a.Sales_Amount,a.Place,
    	Description=CASE 
    		WHEN b.Books IS NULL THEN N'↑新上榜'
    		WHEN a.Place=b.Place THEN N'－'
    		WHEN a.Place>b.Place THEN N'↓'+RTRIM(a.Place-b.Place)+N'位'
    		ELSE N'↑'+RTRIM(b.Place-a.Place)+N'位' END,b.*
    FROM(
    	SELECT Books,Sales_Amount,
    		Place=(SELECT COUNT(Sales_Amount) FROM #1 WHERE Sales_Amount>aa.Sales_Amount)+1
    	FROM #1 aa
    )a LEFT JOIN(
    	SELECT Books,
    		Place=(SELECT COUNT(Sales_Amount) FROM #2 WHERE Sales_Amount>aa.Sales_Amount)+1
    	FROM #2 aa
    )b ON a.Books=b.Books
    ORDER BY a.Place
    GO
    
    --调用
    EXEC p_Qry N'日'
    EXEC p_Qry N'周'
    EXEC p_Qry N'月'
    EXEC p_Qry N'季'
    EXEC p_Qry N'年'