INNER LEFT RIGHT JOIN语句
Sql代码
CREATE TABLE `a` (
`a1` VARCHAR(10) DEFAULT NULL,
`b1` VARCHAR(10) DEFAULT NULL,
`c1` VARCHAR(10) DEFAULT NULL
) ENGINE=INNODB DEFAULT CHARSET=utf8
CREATE TABLE `b` (
`a2` VARCHAR(10) DEFAULT NULL,
`b2` VARCHAR(10) DEFAULT NULL
) ENGINE=INNODB DEFAULT CHARSET=utf8
创建出表，表内数据如下：
SQL语句执行结果图片在语句的下方
Sql代码
#inner join
SELECT A.*,B.*
FROM a INNER JOIN B ON a.a1=b.a2
Sql代码
#left join
SELECT A.*,B.*
FROM a LEFT OUTER JOIN b ON a.a1 = b.a2
Sql代码
#right join
SELECT A.*,B.*
FROM a RIGHT OUTER JOIN b ON a.a1 = b.a2
Sql代码
#full outer join union
SELECT A.*,B.*
FROM a LEFT OUTER JOIN b ON a.a1 = b.a2
UNION
SELECT A.*,B.*
FROM a RIGHT OUTER JOIN b ON a.a1 = b.a2
Sql代码
SELECT A.*, B.* FROM A,B
Sql代码
SELECT A.*,B.*
FROM a JOIN b ON a.a1 = b.a2
默认是inner join