【mysql】Every derived table must have its own alias

关于这条报错信息，意思是指每个派生出来的表都必须有一个自己的别名。

_mysql_exceptions.OperationalError: (1248, 'Every derived table must have its own alias')

如下两条select语句可以说明这个问题：

select count(*) from (select * from A where uuid='123') ;   // error

select count(*) from (select * from A where uuid='123') as a ;   // ok