SQL Join方式总结

SQL Join方式总结：（一共7种）

1，内连接

SELECT FROM TABLEA A INNER JOIN TABLEB B ON A.key=B.key

2，全外连接 Mysql暂不支持

SELECT FROM TABLEA A FULL OUTER JOIN TABLEB B ON A.key=B.key

3，全外连接-差集 Mysql暂不支持

SELECT FROM TABLEA A FULL OUTER JOIN TABLEB B ON A.key=B.key WHERE A.key IS NULL OR B.key IS NULL

4，左(外)连接

SELECT FROM TABLEA A LEFT JOIN TABLEB B ON A.key=B.key

5，左(外)连接-左表无连接部分

SELECT FROM TABLEA A LEFT JOIN TABLEB B ON A.key=B.key WHERE B.key IS NULL

6，右(外)连接

SELECT FROM TABLEA A RIGHT JOIN TABLEB B ON A.key=B.key

7，右(外)连接-右表无连接部分

SELECT FROM TABLEA A RIGHT JOIN TABLEB B ON A.key=B.key WHERE A.key IS NULL