mysql - 使用mysql将表与自身连接

Question

当我在 phpmyadmin 上使用 mariadb 服务器在 mysql 上编写此行时，在 a.cpid = b.cid 附近出现意外错误

select a.cid, a.cname as 'cname', b.cname as 'pname'
from categories as a left OUTER JOIN as b ON a.cpid = b.cid

MySQL said:
#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'as b ON a.cpid = b.cid LIMIT 0, 25' at line 1

Answer 1

您缺少表名(下面的第二类):

select a.cid, a.cname as 'cname', b.cname as 'pname' 
from categories as a 
left OUTER JOIN categories as b ON a.cpid = b.cid