create table actor_name ( first_name varchar(45) not null primary key, last_name varchar(45) not null) insert into actor_name select a.first_name,a.last_name from actor as a create table if not exists actor_name( first_name varchar(45) not null, last_name varchar(45) not null); -- 创建表 insert into actor_name select first_name,last_name from actor; -- 插入查询结果 为什么上面的运行错误，下面的确实对的呢