本文將詳細介紹MySQL中如何實作以SQL查詢傳回的結果集取交集的實作方法，需要的朋友可以參考
1
MySQL中如何實作以下SQL查詢
(SELECT S.Name
FROM STUDENT S, TRANSCRIPT T
WHERE S.StudId = T.StudId AND T.CrsCode = 'CS305' )
INTERSECT
(SELECT S.Name
FROM STUDENT S, TRANSCRIPT T
WHERE S.StudId = T.StudId AND T.CrsCode = 'CS315')
請各位不吝賜教，各位不忠小弟先謝過~
解：
取交集
select a.* from
(
SELECT S.Name
FROM STUDENT S, TRANSCRIPT T
WHERE S.StudId = T.StudId AND T.CrsCode = 'CS305'
) as a
cross join
(
SELECT S.Name
FROM STUDENT S, TRANSCRIPT T
WHERE S.StudId = T.StudId AND T.CrsCode = 'CS315'
) as b on a.Name = b.Name;
2.
SELECT * FROM (
SELECT DISTINCT col1 FROM t1 WHERE...
UNION ALL
SELECT DISTINCT col1 FROM t1 WHERE...
) AS tbl
GROUP BY tbl.col1 HAVING COUNT( *) = 2
3.
交集：
SELECT * FROM table1 AS a JOIN table2 AS b ON a.name =b.name
範例：
表a:
FieldA
001
002
003
表b:
FieldA
001
002
003
004
請教如何才能得出以下結果集，即表A, B行交集
FieldA
001
002
003
答案：select a.FieldA from a inner join b on a.FieldA =b.FieldA
差集：
NOT IN 表示差集
SELECT * FROM table1 WHERE name NOT IN (SELECT name FROM table2)
以上是mysql 查詢結果取交集的方法的詳細內容。更多資訊請關注PHP中文網其他相關文章！
