SQLite的選擇和分組跨

Question

我有了兩個列的SQLite表稱爲匹配列匹配：列1和列2包含整數值：

column1 column2 
------------------ 

5   6 
6   8 
8   9 
90   91 
1   20 
10   20 

我想匹配在任一列中發現重複的號碼，加入他們的行列包括比賽第二個值，讓自己的搜索結果中的回報將是：

5, 6, 8, 9 
1, 20, 10 

（不包括通知，90和91都沒有比賽，因此）。

我的「猜測」在做這樣的：

SELECT column1, column2 
FROM match 
WHERE column2 
IN (SELECT column1 
    FROM match 
    GROUP BY column1 HAVING (COUNT(column1) > 0)) 
    UNION 
    SELECT column1, column2 
    FROM match 
    WHERE column1 
    IN (SELECT column2 
     FROM match 
     GROUP BY column1 HAVING (COUNT(column2) > 0)) 
     UNION 
     SELECT column1, column2 
     FROM match 
     WHERE column1 
     IN (SELECT column1 
      FROM match 
      GROUP BY column1 HAVING (COUNT(column1) > 1)) 
      UNION 
      SELECT column1, column2 
      FROM match 
      WHERE column2 
      IN (SELECT column2 
       FROM match 
       GROUP BY column2 HAVING (COUNT(column2) > 1)) 

，結果幾乎是我所需要的：

5 6 
6 8 
8 9 
1 20 
10 20 

但我真正需要的是有結果不知何故分組。例如：

（5,6，8,9）（1，10，20）

這是可能的？而我的SQL嘗試是否過於複雜？

Answer 1

我想這是你想要什麼：http://sqlfiddle.com/#!7/05747/9

SELECT column1 as newColumn 
FROM match WHERE column1 in (

SELECT myColumn 
FROM(

SELECT count(*) as cnt, myColumn 
FROM (
SELECT column1 as myColumn 
FROM match 
UNION ALL 
SELECT column2 as myColumn 
FROM match 
) x 
GROUP BY myColumn 
HAVING cnt > 1 
) y 
) OR column2 in (
SELECT myColumn 
FROM(

SELECT count(*) as cnt, myColumn 
FROM (
SELECT column1 as myColumn 
FROM match 
UNION ALL 
SELECT column2 as myColumn 
FROM match 
) x 
GROUP BY myColumn 
HAVING cnt > 1 
) y 
) 
UNION 
SELECT column2 as newColumn 
FROM match WHERE column1 in (

SELECT myColumn 
FROM(

SELECT count(*) as cnt, myColumn 
FROM (
SELECT column1 as myColumn 
FROM match 
UNION ALL 
SELECT column2 as myColumn 
FROM match 
) x 
GROUP BY myColumn 
HAVING cnt > 1 
) y 
) OR column2 in (
SELECT myColumn 
FROM(

SELECT count(*) as cnt, myColumn 
FROM (
SELECT column1 as myColumn 
FROM match 
UNION ALL 
SELECT column2 as myColumn 
FROM match 
) x 
GROUP BY myColumn 
HAVING cnt > 1 
) y 
)