"""add shape field to fruits table
Revision ID: 1a2b3c4d5e6f
Revises: 0002
Create Date: 2024-01-20 10:00:00.000000
"""
from alembic import op
import sqlalchemy as sa

# revision identifiers, used by Alembic.
revision = '1a2b3c4d5e6f'
down_revision = '0002'
branch_labels = None
depends_on = None

def upgrade():
    # SQLite doesn't support adding NOT NULL columns without defaults
    # We need to use batch operations for this
    with op.batch_alter_table('fruits') as batch_op:
        batch_op.add_column(sa.Column('shape', sa.String(), nullable=True))
        # Update existing rows with a default value
        op.execute("UPDATE fruits SET shape = 'unknown' WHERE shape IS NULL")
        # Now make the column NOT NULL
        batch_op.alter_column('shape',
                            existing_type=sa.String(),
                            nullable=False)

def downgrade():
    with op.batch_alter_table('fruits') as batch_op:
        batch_op.drop_column('shape')