SELECT * FROM table1 LEFT JOIN table2 ON table1.id = table2.id LIMIT 1;
参考:https://geek-docs.com/mysql/mysql-ask-answer/75_mysql_left_join_only_first_row.html
分组再加limit:left join右表记录不唯一。
参考2:https://blog.csdn.net/u010089432/article/details/52165026
参考3:http://www.mobiletrain.org/about/BBS/257113.html
参考4:...