[DDC-2225] Discriminator column is not considered correctly for class table inheritance

Tue, 12 Feb 2013 10:45:29 +0000

Imagine having a class table inheritance for Employee and Person:

class Person {} => is mapped to table "person"
class Employee extends Person {} is mapped to table "person_employee"

When selecting "SELECT e FROM Employee" the SqlWalker will not generate a WHERE condition for a correct discriminator column value (e.g. "employee"). The ORM seems to trust on the generated INNER JOIN (person.id = person_employee.id).

Of course the table person_employee should only contain rows for Employee ojects. But if you have a discriminator value "person" for a row matching an Employee row, the repository will return a Person object although we selected from Employee.

A simple fix is to add the correct DQL expression:
SELECT e FROM Employee WHERE e INSTANCE OF Employee

Is there any reason, why the discriminator column is only considered for single table inheritance explicitly (see https://github.com/doctrine/doctrine2/blob/master/lib/Doctrine/ORM/Query/SqlWalker.php#L426)?

Doctrine Project

[DDC-2225] Discriminator column is not considered correctly for class table inheritance