Doctrine Relations (Symfony)
Use when
- Mapping a
ManyToOne, OneToMany, ManyToMany or OneToOne and choosing the owning side.
- Deciding between
cascade and orphanRemoval for child entities.
- A relation does not persist (only the inverse side was set), or
contains() is slow on a large inverse collection.
- Splitting entities across several entity managers.
Default workflow
- Pick the owning side (holds the foreign key,
ManyToOne with inversedBy) and the inverse side (OneToMany with mappedBy).
- Initialize collections with
ArrayCollection in the constructor, and write addX() and removeX() helpers that keep both sides in sync.
- Use
cascade: ['persist'] for aggregates saved together, and orphanRemoval: true only for true composition.
- Mark large inverse collections
fetch: 'EXTRA_LAZY', or test membership from the owning side.
- Add fetch joins where a use case reads the relation, to avoid N+1 queries.
- With several entity managers, keep each entity set in one manager and fetch repositories through
ManagerRegistry.
Guardrails
- Doctrine persists what the owning side holds: always set the
ManyToOne reference.
- Avoid
cascade: ['remove'] on large collections (one DELETE per row), and never use orphanRemoval on shared entities.
- A relation cannot span two entity managers.
- For a non-default entity manager, fetch repositories with
ManagerRegistry::getRepository(Entity::class, 'name').
Progressive disclosure
- Use this file for execution posture and risk controls.
- Open references when deep implementation details are needed.
Output contract
- Entity mappings with the owning and inverse sides, cascade and orphan decisions.
- Fetch strategy for large collections and hot paths.
- Result of
doctrine:schema:validate.
References
