"""add created_at to tasks

Revision ID: ac2bd309d20c
Revises: 40867bd0dcc8
Create Date: 2020-05-20 12:36:53.685254

"""
from alembic import op
import sqlalchemy as sa


# revision identifiers, used by Alembic.
revision = 'ac2bd309d20c'
down_revision = '40867bd0dcc8'
branch_labels = None
depends_on = None


def upgrade():
    # Requires batching for non-constant default under SQLite.
    with op.batch_alter_table('tasks', recreate='always') as batch:
        batch.add_column(
            sa.Column(
                'created_at',
                sa.DateTime,
                server_default=sa.func.current_timestamp(),
                nullable=False
            )
        )


def downgrade():
    with op.batch_alter_table('tasks') as tasks:
        tasks.drop_column('created_at')