Relationships

Germinator tries to be smart about dependencies and references between entries. Because of the enforced globally unique $id fields, we can allow your seeds to reference each other from within files.

A simple relationship looks like:

germinator: v2
synchronize: true

entities:
  - Position:
      $id: position-janitor
      name: Janitor

  - Employee:
      $id: bob-joe
      fullName: Bob Joe
      positionId:
        $id: position-janitor

This looks pretty innocent, but the magic happens in the $id: position-janitor.

When germinator runs the seed, it knows a few things:

1. the employee.position_id column is a foreign key referencing position.id
2. when creating bob-joe, we need to create position-janitor first, to populate position_id

When you don't specify $idColumnName, germinator assumes that your tables have an id field.

We can be more explicit:

germinator: v2
synchronize: true

entities:
  - Position:
      $id: position-janitor
      $idColumnName: guid
      name: Janitor

  - Employee:
      $id: bob-joe
      fullName: Bob Joe
      positionGuid:
        $id: position-janitor
        $idColumn: guid

Composite IDs

Germinator has support for composite IDs. How you set this up is fairly straightforward.

germinator: v2
synchronize: true

entities:
  - BlogPostCategories:
      $id: post1-category1
      $idColumnName: [post_id, category_id]
      postId:
        $id: post1
      categoryId:
        $id: category1

  - ReferenceToCompositeTable:
      $id: foobar
      referencePostId:
        $id: post1-category1
        $idColumn: post_id
      referenceCategoryId:
        $id: post1-category1
        $idColumn: category_id

This setup is manual, but mostly by design. We don't want to hide what's going on in the SQL layer.

Diamond Dependencies and Delete Order

Germinator can occasionally stumble when deleting many entries that rely on each other. Unfortunately, this is a limitation because of the way we store information about entered seeds.

Germinator will delete seeds in inverse-insertion order, so most of the time things work out. But you should be aware of this limitation in case you need to delete entries manually.

You're free to delete rows that germinator created, if you know that they will be removed next time germinator is run.