Question

代码如下：

SELECT DISTINCT * 
FROM tblWCS_Bulletins 
INNER JOIN tblWCS_BulletinComments ON tblWCS_BulletinComments.BulletinID = tblWCS_Bulletins.RowID 
WHERE VisibleTo LIKE ('%@' + @UserID + '@%') 
  AND CommentString LIKE ('%'   + @SearchString + '%')
   OR VisibleTo LIKE ('%@' + @UserID + '@%') 
  AND BulletinHeader LIKE ('%' +   @SearchString + '%') 
   OR VisibleTo LIKE ('%@' + @UserID + '@%') 
  AND BulletinContent LIKE ('%' + @SearchString + '%'

但如果在第二个表中找到多个结果，则返回第一个表中行的重复项。我希望结果只返回第一个表中的一行，即使在找到的第二个连接表中有多行。

Answer 1

修改您的查询，如下所示，此查询将仅从具有不同值的第一个表中获取数据。

SELECT DISTINCT tblWCS_Bulletins.* 
FROM tblWCS_Bulletins 
INNER JOIN tblWCS_BulletinComments 
ON tblWCS_BulletinComments.BulletinID = tblWCS_Bulletins.RowID 
WHERE VisibleTo LIKE ('%@' + @UserID + '@%') AND CommentString LIKE ('%'   + @SearchString + '%')
OR VisibleTo LIKE ('%@' + @UserID + '@%') AND BulletinHeader LIKE ('%' +   @SearchString + '%') 
OR VisibleTo LIKE ('%@' + @UserID + '@%') AND BulletinContent LIKE ('%' + @SearchString + '%'

希望这有帮助！

Answer 2

大概你想要每BulletinId行一行：

SELECT *
FROM (SELECT . . .,  -- list columns you want
             ROW_NUMBER() OVER (PARTITION BY BulletinId ORDER BY BulletinId) as seqnum
      FROM tblWCS_Bulletins b INNER JOIN
           tblWCS_BulletinComments bc
           ON bc.BulletinID = b.RowID 
      WHERE (VisibleTo LIKE ('%@' + @UserID + '@%') AND CommentString LIKE ('%'   + @SearchString + '%')) OR
            (VisibleTo LIKE ('%@' + @UserID + '@%') AND BulletinHeader LIKE ('%' +   @SearchString + '%')) OR 
            (VisibleTo LIKE ('%@' + @UserID + '@%') AND BulletinContent LIKE ('%' + @SearchString + '%'))
     ) x
WHERE seqnum = 1;

您应该明确列出列以避免重复的列名称（子查询中不允许）。

您可以通过调整ORDER BY子句确定第二个表中的哪一行。

选择DISTINCT值，where子句在内连接

2 个答案: