没有找到与Doctrine2的多态关联领域 [英] Not finding field in polymorphic association with Doctrine2

问题描述

我有一个多态关联（Class Table Inheritance），我需要使用DQL查询特定子类的实体，可以使用WHERE子句中的x INSTANCE OF Entity来完成。现在我需要为这个小孩类设置条件，但是我收到这个错误：

类人没有关联名为student_field_1

Person = Parent Class

Employee =子类

学生=子类

有没有办法，你以某种方式告诉学说，该人实际上是一个学生，并允许我把学生字段放在WHERE？

解决方案

如果您只是询问学生，那么为什么不这样做？

  SELECT s FROM Student s WHERE s.student_field_1 = ... 
  

I have a polymorphic association (Class Table Inheritance) and I need use DQL to query entities of a specific child class wich can be done using "x INSTANCE OF Entity" in WHERE clause. Now I need to put conditions specific for that child class but I get this error:

"Class Person has no association named student_field_1"

Person = Parent Class

Employee = Child class

Student = Child class

is there any way yo cast of somehow tell Doctrine that the Person is actually a Student and to allow me to put Student fields in the WHERE?

解决方案

If you're only querying students, then why don't you just do this?

SELECT s FROM Student s WHERE s.student_field_1 = ...

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