Question

您好我在下面有这个SQL但是我遇到了问题我将出勤记录保存在出勤表和StaffComments表中的注释但我也有一个表ContractorsComments女巫使用相同的出勤表和NotesID列在某些情况下增加了一倍

承包商与我试图使用的员工有不同的PRN

在哪里dbo.StaffComments.PRN = 15458 AND dbo.Attendance.PRN = 15458

但这导致它只显示两个表中找到匹配的记录

我需要SQL来显示dbo.StaffComments表中的所有Notes，但只显示dbo中的SAME PRN记录.Attendance

 SELECT Comments, PRN, id, DateMade, UserID, Reason, EventDate, AttendanceID, Sdate, Edate
        FROM ( 
        SELECT dbo.StaffComments.Comments, dbo.StaffComments.PRN, dbo.StaffComments.id, dbo.StaffComments.DateMade, dbo.StaffComments.UserID, dbo.StaffComments.Reason, 
        dbo.StaffComments.EventDate, dbo.Attendance.id AS AttendanceID, dbo.Attendance.Sdate, dbo.Attendance.Edate, ROW_NUMBER() OVER (ORDER BY dbo.StaffComments.ID DESC) AS RowNum 
        FROM dbo.StaffComments 
        LEFT JOIN dbo.Attendance
        ON dbo.StaffComments.id = dbo.Attendance.NoteID     
        WHERE dbo.StaffComments.PRN = 15458  
        ) AS notes 
        WHERE notes.RowNum BETWEEN 1 AND 100

Answer 1

将您的ON子句更新为PRN上的JOIN

LEFT JOIN dbo.Attendance
        ON dbo.StaffComments.id = dbo.Attendance.NoteID     
        AND dbo.StaffComments.PRN = dbo.Attendance.PRN 
        WHERE dbo.StaffComments.PRN = 15458

您更新的查询将如下所示：

SELECT Comments, PRN, id, DateMade, UserID, Reason, EventDate, AttendanceID, Sdate, Edate
        FROM ( 
        SELECT dbo.StaffComments.Comments, dbo.StaffComments.PRN, dbo.StaffComments.id, dbo.StaffComments.DateMade, dbo.StaffComments.UserID, dbo.StaffComments.Reason, 
        dbo.StaffComments.EventDate, dbo.Attendance.id AS AttendanceID, dbo.Attendance.Sdate, dbo.Attendance.Edate, ROW_NUMBER() OVER (ORDER BY dbo.StaffComments.ID DESC) AS RowNum 
        FROM dbo.StaffComments 
        LEFT JOIN dbo.Attendance
        ON dbo.StaffComments.id = dbo.Attendance.NoteID
        AND dbo.StaffComments.PRN = dbo.Attendance.PRN 
        WHERE dbo.StaffComments.PRN = 15458  
        ) AS notes 
        WHERE notes.RowNum BETWEEN 1 AND 100

Answer 2

你为什么要加入staffcomments.id和attendance.noteid？

您需要像以前一样加入PRN，但需要加入外部联接。

SELECT Comments, PRN, id, DateMade, UserID, Reason, EventDate, AttendanceID, Sdate, Edate
        FROM ( 
        SELECT dbo.StaffComments.Comments, dbo.StaffComments.PRN, dbo.StaffComments.id, dbo.StaffComments.DateMade, dbo.StaffComments.UserID, dbo.StaffComments.Reason, 
        dbo.StaffComments.EventDate, dbo.Attendance.id AS AttendanceID, dbo.Attendance.Sdate, dbo.Attendance.Edate, ROW_NUMBER() OVER (ORDER BY dbo.StaffComments.ID DESC) AS RowNum 
        FROM dbo.StaffComments 
        LEFT OUTER JOIN dbo.Attendance
        ON dbo.StaffComments.PRN = dbo.Attendance.PRN    
        WHERE dbo.StaffComments.PRN = 15458  
        ) AS notes 
        WHERE notes.RowNum BETWEEN 1 AND 100

SQL语句LEFT JOIN无法获得我正在寻找的结果

2 个答案: