symfony - Doctrine query not returning the same result depending on the order of the join

Question

I want to do one query, and I thought I could write it in the following two ways:

SELECT c, p
FROM MyBundle:Car c
    JOIN c.person p
WHERE
    p.name =  :name

and

SELECT c, p
FROM MyBundle:Person p
    JOIN p.car c
WHERE
    p.name =  :name

Since in both cases I was asking for "c, p" in that particular order, I was expecting the query to return the same thing, however, in the first case the object I get is of the type Car and on the second case is of type Person.

I don't understand why this happens, any light would be appreciated.

Answer 1

第一个说：给我每辆车都附在一个人身上，其中人的名字是 :name。当然，这是一个汽车清单。

第二个说给我每个连接到汽车的人，其中人的名字是：name。当然，这是一份人员名单。

由于它们是连接的，因此学说热切将相关实体加载为主要选择的字段，这由 from 子句指示。

基本上，这是面向对象的视图，这就是 dql 的工作方式。您认为它们应该相同的论点是面向元组的视图，这就是 sql 的工作方式。掌握这一概念对于有效使用学说至关重要。