如何在postgres中使用alembic回填递增的id

CREATE TABLE my_table (
    id SERIAL PRIMARY KEY,
    column1 VARCHAR(255),
    column2 INTEGER
);

alembic init my_migration

sqlalchemy.url = postgresql://username:password@localhost:5432/my_database

from alembic import op
import sqlalchemy as sa

def upgrade():
    op.add_column('my_table', sa.Column('id', sa.Integer(), nullable=False))
    op.execute("UPDATE my_table SET id = nextval('my_table_id_seq')")
    op.alter_column('my_table', 'id', nullable=False, server_default=sa.text('nextval(\'my_table_id_seq\')'))

alembic upgrade head