为什么表中的名称列重复？答案

【问题标题】：Why name column in table repeats itself?为什么表中的名称列重复？
【发布时间】：2015-03-12 21:42:33
【问题描述】：

你好，我已经处理这个查询很多天了，最后除了 1 个问题之外几乎完成了。

它给了我这个输出

N   ConductorName   Denomination    totaltransactions   totalamount
1   NULL               NULL              1882             41610.00
1   Imran              30.00             199              5970.00
2   NULL               Imran total       199              5970.00
1   Shoaib             30.00             99               2970.00
2   NULL               Shoaib total      99               2970.00
1   Umair              10.00             792              7920.00
2   Umair              15.00             396              5940.00
3   Umair              30.00             99               2970.00
4   Umair              40.00             99               3960.00
5   Umair              60.00             198              11880.00
6   NULL               Umair total       1584             32670.00

很好，但我想消除 ConductorName 列中的名称重复，即

预期：

N   ConductorName   Denomination    totaltransactions   totalamount
1   NULL               NULL              1882             41610.00
1   Imran              30.00             199              5970.00
2   NULL               Imran total       199              5970.00
1   Shoaib             30.00             99               2970.00
2   NULL               Shoaib total      99               2970.00
1   Umair              10.00             792              7920.00
2   NULL               15.00             396              5940.00
3   NULL               30.00             99               2970.00
4   NULL               40.00             99               3960.00
5   NULL               60.00             198              11880.00
6   NULL               Umair total       1584             32670.00

所以每个名字都有 1 次，但数据完好无损。

SP：

ALTER PROCEDURE [dbo].[ReportConductorPerformance]
@FromDate DATE,
@ToDate DATE
AS
BEGIN
    SELECT        ROW_NUMBER() OVER (PARTITION BY c.name order by c.name) 'N',CASE WHEN isnull(CAST(T .amount AS varchar(30)), c.name + ' total') LIKE '%total%' THEN NULL ELSE c.name END AS ConductorName, 
                             ISNULL(CAST(T.Amount AS varchar(30)), c.Name + ' total') AS Denomination, COUNT(*) AS totaltransactions, SUM(T.Amount) AS totalamount
    FROM            dbo.Tickets AS T INNER JOIN
                             Transport.Conductors AS c ON c.ConductorID = T.Conductor_ID
    WHERE CONVERT(DATE,ServerDateTime) BETWEEN @FromDate and @ToDate
    GROUP BY c.Name, T.Amount WITH ROLLUP 
END

【问题讨论】：

@Blam 抱歉，这是什么意思？我应该害怕什么>

标签： sql sql-server tsql stored-procedures sql-server-2012

【解决方案1】：

虽然我不建议在数据库中处理此问题，但您可以使用 case 语句来获得结果，因为您已经在使用 row_number：

SELECT N, 
       case when N = 1 then ConductorName else NULL end ConductorName, 
       Denomination, 
       totaltransactions, 
       totalamount
FROM (
    SELECT ROW_NUMBER() OVER (PARTITION BY c.name order by c.name) 'N',
        CASE WHEN isnull(CAST(T.amount AS varchar(30)), c.name + ' total') LIKE '%total%' 
             THEN NULL
             ELSE c.name 
        END AS ConductorName, 
        ISNULL(CAST(T.Amount AS varchar(30)), c.Name + ' total') AS Denomination, 
        COUNT(*) AS totaltransactions, 
        SUM(T.Amount) AS totalamount
    FROM dbo.Tickets AS T INNER JOIN
            Transport.Conductors AS c ON c.ConductorID = T.Conductor_ID
    WHERE CONVERT(DATE,ServerDateTime) BETWEEN @FromDate and @ToDate
    GROUP BY c.Name, T.Amount WITH ROLLUP 
) T

【讨论】：

【解决方案2】：

在这种情况下，您可以使用带有简化条件的现有 CASE 语句，只保留分区中第一行的名称。此外，如果您省略了“ELSE”，则默认情况下该值将为 NULL，稍微简化一下。

另一个轻微的简化是使用 SQL Server 的分组方法来检测额外的行，而不是查看是否为 NULL 的值。

SELECT
    ROW_NUMBER() OVER (PARTITION BY c.name order by c.name) 'N',
    CASE
        WHEN T.amount IS NOT NULL AND ROW_NUMBER() OVER (PARTITION BY c.name order by c.name) = 1 THEN c.name
        END AS ConductorName,
    CASE
        WHEN grouping(T.Amount) = 0 THEN CONVERT(VARCHAR(30), T.Amount)
        ELSE c.Name + ' total'
        END AS totaltransactions,
    SUM(T.Amount) AS totalamount
FROM dbo.Tickets AS T
INNER JOIN Transport.Conductors AS c ON c.ConductorID = T.Conductor_ID
WHERE CONVERT(DATE,ServerDateTime) BETWEEN @FromDate and @ToDate
GROUP BY c.Name, T.Amount WITH ROLLUP;

【讨论】：