alembic 遷移表主鍵

表名: files

原表的主鍵名爲 md5，現在添加新主鍵 id，修改生成的遷移文件:

op.drop_constraint('md5', 'files', type_='primary') # 手動添加
op.add_column('files', sa.Column('id', ...))
op.create_primary_key('id', 'files', ['id']) # 手動添加
op.alter_column('files', 'md5', ...)

參考:

• [drop_constraint] https://alembic.sqlalchemy.org/en/latest/ops.html?highlight=operations#alembic.operations.Operations.drop_constraint
• [create_primary_key] https://alembic.sqlalchemy.org/en/latest/ops.html?highlight=operations#alembic.operations.Operations.create_primary_key