不能得到源碼查詢

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; 

這sqlite的代碼返回下面對正確的順序：

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

在對的名稱是正確的，但他們中的一些應圍繞顯示的其他方式，也就是說，結果應該是：

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

如果有人能指出我做錯了什麼，我將不勝感激。預先感謝您提供的任何幫助。

Answer 1

您可以將<更改爲<>內部select，然後您將獲得每個對兩次，然後在外部選擇中添加名稱約束，如（查找### HERE）。 另外我想你想ASC不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