Question

客户需要一种工具来显示几个月前客户每月的不成功付款。开始月份和返回的月份数应由用户定义所有付款都记录在同一张表中。同一客户在过去几个月中可能有也可能没有付款。这是一张表格，每笔付款都有多行，所以我需要使用分组依据。

我正在尝试找出查询信息的最佳方法。

我想它应该是动态构建的（对吗？可以在没有动态sql的情况下完成吗？），并且在搜索网络时看到了不同的方法：

使用案例，例如以下查询，在select子句中动态添加行：SQL query to compare product sales by month
将每个月要比较的UNIONS动态添加到同一张表中
将每个月要比较的左联接动态添加到同一张表中

方法1的概念代码：

DECLARE @month int, @monthNum int
SET @month = 103
SET @monthNum = 1

SELECT
    name,ID,Property
    ,MAX(CASE WHEN month = @month THEN month ELSE 0 END) AS month 
    ,SUM(CASE WHEN month = @month THEN paymentSum ELSE 0 END) AS paymentSum 
    ,MAX(CASE WHEN month = @month THEN PaymentFailReason ELSE 0 END) AS PaymentFailReason
    ,MAX(CASE WHEN month = @month -1 THEN month ELSE 0 END) AS monthMinusOne
    ,SUM(CASE WHEN month = @month -1 THEN paymentSum ELSE 0 END) AS paymentSumMinusOne
    ,MAX(CASE WHEN month = @month -1 THEN PaymentFailReason ELSE 0 END) AS PaymentFailReasonMinusOne

FROM
    payments

WHERE
    month BETWEEN @month -@monthNum AND @month AND status = 2

GROUP BY
name,ID,Property

状态= 2表示付款失败。

在这种情况下是否有首选的解决方案？

一种方法比其他方法更有效吗？

样本数据：

month   ID  name    Property    paymentSum  PaymentFailReason   Status

100      1  Aron       A            100       Has No money         2
100      2  Burt       B            100       Has No money         2
100      3  Carl       C            50        Has No money         2
101      1  Aron       A            50        Has No money         2
101      2  Burt       B            50        Has No money         2
101      3  Carl       C            50        Has No money         2
102      1  Aron       A            100       Has No money         2
102      2  Burt       B            100                            1
102      3  Carl       C            100       Has No money         2
103      1  Aron       A            102       Has No money         2
103      2  Burt       B            102       Has No money         2
103      3  Carl       C            102                            1

查询上述第103个月和1个月前的数据的结果应为：

month   ID  name    Property    paymentSum  PaymentFailReason   Status  monthMinusOne   paymentSumMinusOne  PaymentFailReasonMinusOne

103      1  Aron        A            102       Has No money        2         102                100               Has No money
103      2  Burt        B            102       Has No money        0         102                0                 0

卡尔成功支付了103英镑，因此他不在结果中。

Burt在102日成功付款，因此该月的数据无关紧要（全为零）。

编辑：我创建了一个动态SQL查询，该查询循环循环创建用户定义的月份数的案例。需要一段时间...我想念什么？左联接或工会会更好吗？

Answer 1

自己弄清楚。希望这对其他人有帮助...

选项1显然效果很好。由于某种原因，当我第一次在SSMS中运行它时，花了20个月才花了10秒钟以上的时间-但这只是第一次运行。

这很奇怪。（也许服务器在第一次运行后就适应了？）

从那时起，它运行起来非常快，几个月后又不到一秒钟。

这是我所做的：（改进和样式说明将不胜感激！）

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE PROCEDURE [dbo].[CompareFailedPayments](@month int , @NumOfMonths int) 
AS

BEGIN
DECLARE @SqlHead nvarchar(max), @Sql nvarchar(max)='', @Crlf nvarchar(max), @counter int
    SET @counter = 0
    SET @Crlf = CHAR(13)+CHAR(10)

SET @SqlHead = 'DECLARE @month int = '+ CAST(@month AS VARCHAR) + @Crlf +
    'SELECT name,IDnumber,Property, ID, month, paymentsum, PaymentFailReason, EncryptedCardNum '

    SET @Sql =  'SELECT name,IDnumber,Property,Payments.ID as Id, Payments.Property as p'+ @Crlf +
    ',MAX(CASE WHEN month = @month THEN month ELSE NULL END) AS month '+ @Crlf +
    ',SUM(CASE WHEN month = @month THEN paymentsum ELSE NULL END) AS paymentsum '+ @Crlf +
    ',MAX(CASE WHEN month = @month THEN PaymentFailReason ELSE NULL END) AS PaymentFailReason '+ @Crlf +
    ',MAX(CASE WHEN month = @month THEN RIGHT(EncryptedCardNum,4) ELSE NULL END) AS EncryptedCardNum '+ @Crlf +
    'FROM Payments '+ @Crlf +
    'INNER JOIN'+ @Crlf +
    'client ON Payments.ID = client.ID'+ @Crlf +
    'WHERE (Payments.month = '+ CAST(@month AS VARCHAR) +') AND (Payments.status = 2)'+ @Crlf +
    'GROUP BY client.name, client.IDnumber, Payments.Property,Payments.ID, Payments.Property '+ @Crlf +
    ') AS Base'+ @Crlf +
    'LEFT OUTER JOIN'+ @Crlf +
    '('+ @Crlf +
    'SELECT Payments.ID as Id1, Payments.Property as p1'+ @Crlf+ @Crlf

    WHILE @counter < @NumOfMonths

        BEGIN
        SET @counter = @counter+1

        SET @Sql = @Sql+',MAX(CASE WHEN month = @month-'+CAST(@counter AS VARCHAR)+' THEN month'+' ELSE NULL END) AS month'+CAST(@counter AS VARCHAR)+ @Crlf +
        ',SUM(CASE WHEN month = @month-'+CAST(@counter AS VARCHAR)+' THEN paymentsum ELSE NULL END) AS paymentsum'+CAST(@counter AS VARCHAR)+ @Crlf +
        ',MAX(CASE WHEN month = @month-'+CAST(@counter AS VARCHAR)+' THEN PaymentFailReason ELSE NULL END) AS PaymentFailReason'+CAST(@counter AS VARCHAR)+ @Crlf +
        ',MAX(CASE WHEN month = @month-'+CAST(@counter AS VARCHAR)+' THEN RIGHT(EncryptedCardNum,4) ELSE NULL END) AS EncryptedCardNum'+CAST(@counter AS VARCHAR)+ @Crlf + @Crlf 

         SET @SqlHead = @SqlHead +', month'+CAST(@counter AS VARCHAR)+', paymentsum'+CAST(@counter AS VARCHAR)+', PaymentFailReason'+CAST(@counter AS VARCHAR)+', EncryptedCardNum'+CAST(@counter AS VARCHAR)+''

        END

     SET @SqlHead = @SqlHead +'  FROM(' + @Crlf

     SET @Sql = @Sql+
    'FROM            Payments'+ @Crlf +
    'WHERE        (Payments.month BETWEEN '+CAST(@month-@NumOfMonths AS VARCHAR)+' AND ' +CAST(@month-1 AS VARCHAR)+') AND (Payments.status = 2)'+ @Crlf +
    'GROUP BY Payments.ID, Payments.Property'+ @Crlf +
    ') AS Back '+ @Crlf +
    'ON Base.ID = Back.m1 and Base.h = Back.h1'  

--PRINT(@sqlHead+@Sql)

EXEC(@sqlHead+@Sql)

动态地压缩同一SQL表中的不同行

1 个答案: