"""parent child relations

Revision ID: 4b6c6a23c639
Revises: 71386dc42f9b
Create Date: 2020-03-18 16:17:09.512280

"""
from alembic import op
import sqlalchemy as sa
import sqlalchemy_utc


# revision identifiers, used by Alembic.
revision = '4b6c6a23c639'
down_revision = '71386dc42f9b'
branch_labels = None
depends_on = None


def upgrade():
    # ### commands auto generated by Alembic - please adjust! ###
    op.add_column('post', sa.Column('parent_id', sa.Integer(), nullable=True))
    op.create_foreign_key(None, 'post', 'post', ['parent_id'], ['id'])
    # ### end Alembic commands ###


def downgrade():
    # ### commands auto generated by Alembic - please adjust! ###
    op.drop_constraint(None, 'post', type_='foreignkey')
    op.drop_column('post', 'parent_id')
    # ### end Alembic commands ###