查询显示表之间不匹配的记录

Question

我有两张桌子.一个是提交给我们的报告表.另一个是临时表,其中包含最终应提交给我们的报告记录.我想只显示临时表中与报告表中的记录不匹配的记录(因此显示仍然必须提交的报告).

示例数据是:

Reports table:

CREATE TABLE [dbo].[Reports]  
(  
    [ReportID] [int] IDENTITY(1,1) NOT NULL,  
    [ReportDate] [date] NULL,  
    [AssessmentID] [int] NOT NULL,  
    [ReportType] [varchar](50) NULL  
);  

AssessmentID    ReportType  ReportID  
1   1st Quarterly   27  
2   1st Quarterly   30  
2   2nd Quarterly   31  
2   3rd Quarterly   32  

QuarterlyReportsDue table:

CREATE TABLE #QuarterlyReportsDue  
(  
AssessmentID INT,  
InstallationDate DATE,  
QuarterlyReportType VARCHAR(50)  
);  

AssessmentID    InstallationDate    QuarterlyReportType  
1   2009-08-14  1st Quarterly  
1   2009-08-14  2nd Quarterly  
1   2009-08-14  3rd Quarterly  
1   2009-08-14  4th Quarterly  
2   2008-05-16  4th Quarterly  
2   2008-05-16  3rd Quarterly  
2   2008-05-16  2nd Quarterly  
2   2008-05-16  1st Quarterly  

我尝试过LEFT OUTER JOINS,但遇到了问题.请看下面的SQL:

SELECT #QuarterlyReportsDue.InstallationDate, #QuarterlyReportsDue.QuarterlyReportType, Reports.ReportType  
FROM #QuarterlyReportsDue  
LEFT OUTER JOIN Reports ON #QuarterlyReportsDue.AssessmentID = Reports.AssessmentID  
WHERE Reports.ReportType IN ('1st Quarterly', '2nd Quarterly', '3rd Quarterly', '4th Quarterly')  
AND Reports.ReportType <> #QuarterlyReportsDue.QuarterlyReportType  
ORDER BY #QuarterlyReportsDue.AssessmentID  

我的结果是:

AssessmentID    QuarterlyReportType ReportType  ReportID  
1   2nd Quarterly   1st Quarterly   27  
1   3rd Quarterly   1st Quarterly   27  
1   4th Quarterly   1st Quarterly   27  
2   4th Quarterly   1st Quarterly   30  
2   4th Quarterly   2nd Quarterly   31  
2   4th Quarterly   3rd Quarterly   32  
2   1st Quarterly   2nd Quarterly   31  
2   1st Quarterly   3rd Quarterly   32  
2   3rd Quarterly   1st Quarterly   30  
2   3rd Quarterly   2nd Quarterly   31  
2   2nd Quarterly   1st Quarterly   30  
2   2nd Quarterly   3rd Quarterly   32  

对于评估1,它很有效,评估2有很多重复.我怎样才能解决这个问题才能显示出理想的结果呢？

AssessmentID    QuarterlyReportType ReportType  
1   2nd Quarterly   1st Quarterly  
1   3rd Quarterly   1st Quarterly  
1   4th Quarterly   1st Quarterly  
2       4th Quarterly     

Answer 1

当您将JOFT JOIN连接到表然后引用WHERE子句中该表的一个列时,您将隐式地将连接转换为INNER JOIN.相反,将这些条件移出WHERE并使它们成为JOIN条件的一部分.

SELECT q.InstallationDate, q.QuarterlyReportType, Reports.ReportType  
    FROM #QuarterlyReportsDue q
        LEFT OUTER JOIN Reports r
            ON q.AssessmentID = r.AssessmentID
                AND q.QuarterlyReportType = r.ReportType  
                AND r.ReportType IN ('1st Quarterly', '2nd Quarterly', '3rd Quarterly', '4th Quarterly')  
    WHERE r.AssessmentID IS NULL /* matching record not found in Reports table */
    ORDER BY #QuarterlyReportsDue.AssessmentID