Question

SELECT DISTINCT
     rev1.name,
     rev2.name

FROM reviewer rev1,
     reviewer rev2,

    (SELECT r1.rid AS r1id,
            r2.rid AS r2id
       FROM rating r1,
            rating r2
      WHERE r1.mID = r2.mID
        AND r1.rid < r2.rID
   ) AS raters

WHERE rev1.rid = raters.r1id
  AND rev2.rid = raters.r2id

ORDER BY rev1.name DESC;

此sqlite代码返回以下对：

Brittany Harris   Chris Jackson
Chris Jackson     Ashley White
Daniel Lewis      Elizabeth Thomas
Elizabeth Thomas  James Cameron
Sarah Martinez    Mike Anderson

对中的名称是正确的，但其中一些应该反过来显示，也就是说，结果应该是：

Ashley White      Chris Jackson
Brittany Harris   Chris Jackson
Daniel Lewis      Elizabeth Thomas
Elizabeth Thomas  James Cameron
Mike Anderson     Sarah Martinez

如果有人能够指出我做错了什么，我将非常感激。提前感谢您提供的任何帮助。

Answer 1

您可以更改＆lt;到＆lt;＆gt;在内部选择内部，然后你将获得每对两次，然后在外部选择中添加名称的约束，类似于（寻找### HERE）。另外我想你想要ASC而不是DESC

SELECT DISTINCT
     rev1.name,
     rev2.name

FROM reviewer rev1,
     reviewer rev2,

    (SELECT r1.rid AS r1id,
            r2.rid AS r2id
       FROM rating r1,
            rating r2
      WHERE r1.mID = r2.mID
        AND r1.rid <> r2.rID  -- HERE - give you each pair twice
   ) AS raters

WHERE rev1.rid = raters.r1id
  AND rev2.rid = raters.r2id
  AND rev1.name < rev2.name  -- HERE - will remove duplicate pairs
  ORDER BY ASC

无法在sqlite查询中获得正确的顺序

1 个答案: