note: this issue seems the same as
When using class table inheritance with multiple levels i.e.:
Object -> SolidObject -> Building -> House
(House inherits from Building, Building from SolidObject, SolidObject from Object)
Object has the discriminator column and mapping. When persisting a new House entity I get a foreign key error because there is no row in the Building table.
I searched in the Code and found the problem. In the class "Doctrine\ORM\Persisters\JoinedSubclassPersister" in function "executeInserts()" around line 146 the array $subTableStmts is first declared and then filled with insert statements. The statement of the House-table is first added, and then the parent-tables (except the root-table "Object", since that one is executed first).
So the order in which the insert statements are executed is:
1 Insert into Object ...
2 Insert into House ... (which causes the error)
3 insert into Building ...
4 Insert into SolidObject
I edited the source to insert into the parent-tables (first SolidObject, then Building) before inserting into the table that belongs to the class that is persisted (House). And this works fine in my case.