* 登陆用户为demo
* 连接字符串串中指定默认库是demo
* 另一个数据库(schema)是demo2,demo用户拥有demo2的所有访问权限
delete f,s from tableF f left join tableS s on f.fid=s.fid
- result=ok
delete f,s from demo.tableF f left join demo.tableS s on f.fid=s.fid
- result=ok
delete f,s from demo2.tableF f left join demo2.tableS s on f.fid=s.fid
- result=error,bad sql grammar :(
delete demo2.tableF,demo2.tableS from demo2.tableF left join demo2.tableS on demo2.tableF.fid=demo2.tableS.fid
- result=ok
可见,mysql在跨库使用schema来执行多表删除时不能给表取别名。