# ALL Joe 想从员工表 ```mysql create table employee( id int primary key auto_increment, dept_id int, name varchar(256), post varchar(16) ) ``` 中找出所有其所在部门没有助理(post 为 `assistant`)的员工信息。由于 Joe 没有其它表的查询权限,他只能查询员工表,这个查询应该是: ## 答案 ```mysql select id, name, dept from employee as o where 'assistant' != all(select post from employee as i where o.dept = i.dept); ``` ## 选项 ### A ```mysql select id, name, dept from employee as o where 'assistant' = all(select post from employee as i where o.dept = i.dept); ``` ### B ```mysql select id, name, dept from employee as o where 'assistant' != all(select post from employee as i where o.dept = i.dept); ``` ### C ```mysql select id, name, dept from employee as o where 'assistant' != all(select post from employee as i); ``` ### D ```mysql select id, name, dept from employee as o where 'assistant' != ANY(select post from employee as i where o.dept = i.dept); ```