oracle和mysql在查询多表时的区别

mysql ：select * from( (select count(id)TOTAL1 from B_1)t1,(select count(id)TOTAL2 from B_17_ASR)t2);

mysql必须给表添加别名

oralce：select * from (select count(id)TOTAL1 from B_1),(select count(id)TOTAL2 from B_17_ASR);

oracle则可以不用