有数据库高手,能帮我具体解释一下这段sql文实现的过程吗?SELECT *FROM AAAWHERE ( NO, PL-NO, CDK, QPF, ZPF, LJB, HNO ) IN (SELECT NO, PL-NO, CDK, QPF, ZPF, LJB, HNO FROM AAAGROUP BY NO, PL-NO, CDK, QPF, ZPF, LJB, HNOHAVING COUNT(*)>1)ORDER BY NO, PL-NO, CDK, QPF, ZPF, LJB, HNO, aa, b
题目
有数据库高手,能帮我具体解释一下这段sql文实现的过程吗?
SELECT *
FROM AAA
WHERE ( NO, PL-NO, CDK, QPF, ZPF, LJB, HNO ) IN (SELECT NO, PL-NO, CDK, QPF, ZPF, LJB, HNO FROM AAA
GROUP BY NO, PL-NO, CDK, QPF, ZPF, LJB, HNO
HAVING COUNT(*)>1)
ORDER BY NO, PL-NO, CDK, QPF, ZPF, LJB, HNO, aa, bb, cc, dd
其中AAA是表名，NO, PL-NO, CDK, QPF, ZPF, LJB, HNO, aa, bb, cc, dd都是表AAA的属性。