"""Fix pr project_from key

Revision ID: 61ac23e35f86

Revises: 47f5fab6f46a

Create Date: 2017-12-05 16:59:17.117199

"""

# revision identifiers, used by Alembic.

revision = '61ac23e35f86'

down_revision = '47f5fab6f46a'

from alembic import op

import sqlalchemy as sa

def upgrade():

    """ Alter the pull_requests table to update the foreign key to set null

    on delete.

    """

    op.drop_constraint(

        'pull_requests_project_id_from_fkey',

        'pull_requests',

        type_='foreignkey')

    op.create_foreign_key(

        name='pull_requests_project_id_from_fkey',

        source_table='pull_requests',

        referent_table='projects',

        local_cols=['project_id_from'],

        remote_cols=['id'],

        onupdate='cascade',

        ondelete='set null',

    )

def downgrade():

    """ Alter the pull_requests table to update the foreign key to cascade

    on delete.

    """

    op.drop_constraint(

        'pull_requests_project_id_from_fkey',

        'pull_requests',

        type_='foreignkey')

    op.create_foreign_key(

        name='pull_requests_project_id_from_fkey',

        source_table='pull_requests',

        referent_table='projects',

        local_cols=['project_id_from'],

        remote_cols=['id'],

        onupdate='cascade',

        ondelete='cascade',

    )