SELECT 字段1 "start",字段2 "end"
FROM (SELECT 字段1 ,字段2
FROM 表
INTERSECT
SELECT 字段2,字段1
FROM 表
GROUP BY 字段1,字段2)
ORDER BY ABS(ASCII(字段1)-ASCII(字段2));
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LZ try 一下!
SELECT c.字段1, c.字段2
FROM 表1 AS c, [SELECT DISTINCT a.字段1, a.字段2
FROM 表1 AS a, 表1 AS b
WHERE a.字段2=b.字段1 AND a.字段1=b.字段2]. AS d
WHERE d.字段1 = c.字段1 AND d.字段2 = c.字段2
ORDER BY c.字段1;