没有找到与Doctrine2多态关联的字段

Question

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?

Answer 1

It sounds like a "Mapped Superclass" would be more suited to what your trying to do as it doesn't require an explicit link between parent / child, its just simple inheritance.

http://docs.doctrine-project.org/projects/doctrine-orm/en/2.0.x/reference/inheritance-mapping.html#mapped-superclasses

With Class Table Inheritance your required to provide discriminator map that links the two entities through a key.

"The table of a child class should be linked to the table of a parent class through a foreign key constraint"