考虑如下2个SQL语句： select last_name from employees join departments on employees.department_id = departments.department_id where department_name='Executive'; 和 select last_name from employees where department_id in (select department_id from departments where department_name='Executive'); 关于这2个语句描述正确的是？ 答案: 1. 2条语句运行都会成功，即使有2个部门名称是'Executive'; 2. 这2条语句将产生相同的结果;