Inner left right join statement

Inner left right join statement SQL code CREATE TABLE 'A' ('a1' VARCHAR (10) DEFAULT NULL, 'b1 'varchar (10) DEFAULT NULL, 'c1' VARCHAR (10) default null) ENGINE = innodb default charset = utf8 www.2cto.com create table 'B' ('a2 'VARCHAR (10) DEFAULT NULL, 'b2' VARCHAR (10) DEFAULT NULL) ENGINE = innodb default charset = utf8: The data in the table is as follows: SQL statement execution result image: SQL code below the statement # inner join SELECT. *, B. * FROM a inner join B ON. a1 = B. a2 www.2cto.com SQL code # left join SELECT. *, B. * FROM a left outer join B ON. a1 = B. a2 SQL code # right join SELECT. *, B. * FROM a right outer join B ON. a1 = B. a2 SQL code # full outer join union SELECT. *, B. * FROM a left outer join B ON. a1 = B. a2 UNION www.2cto.com select. *, B. * FROM a right outer join B ON. a1 = B. a2 SQL code SELECT. *, B. * from a, B SQL code SELECT. *, B. * FROM a JOIN B ON. a1 = B. a2 is inner join by default.