当upgrade失败后，如何回退到之前的迁移版本
migrate后upgrade失败后的报错：
(vpp_agent_venv3.7) [root@localhost source]# python app-migrate.py db migrate
INFO [alembic.runtime.migration] Context impl MySQLImpl.
INFO [alembic.runtime.migration] Will assume non-transactional DDL.
INFO [alembic.autogenerate.compare] Detected removed index 'ix_in_router_manager_room_id' on 'in_router_manager'
INFO [alembic.autogenerate.compare] Detected removed foreign key (room_id)(id) on table in_router_manager
INFO [alembic.autogenerate.compare] Detected removed column 'in_router_manager.room_id'
Generating /srv/web_develop/vpp_agent_dev/agent/source/migrations/versions/8400cd3396af_.py ... done
(vpp_agent_venv3.7) [root@localhost source]# python app-migrate.py db upgrade
INFO [alembic.runtime.migration] Context impl MySQLImpl.
INFO [alembic.runtime.migration] Will assume non-transactional DDL.
INFO [alembic.runtime.migration] Running upgrade 48a794328fe9 -> 8400cd3396af, empty message
Traceback (most recent call last):
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/sqlalchemy/engine/base.py", line 1193, in _execute_context
context)
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/sqlalchemy/engine/default.py", line 509, in do_execute
cursor.execute(statement, parameters)
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/pymysql/cursors.py", line 170, in execute
result = self._query(query)
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/pymysql/cursors.py", line 328, in _query
conn.query(q)
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/pymysql/connections.py", line 516, in query
self._affected_rows = self._read_query_result(unbuffered=unbuffered)
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/pymysql/connections.py", line 727, in _read_query_result
result.read()
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/pymysql/connections.py", line 1066, in read
first_packet = self.connection._read_packet()
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/pymysql/connections.py", line 683, in _read_packet
packet.check_error()
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/pymysql/protocol.py", line 220, in check_error
err.raise_mysql_exception(self._data)
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/pymysql/err.py", line 109, in raise_mysql_exception
raise errorclass(errno, errval)
pymysql.err.InternalError: (1553, "Cannot drop index 'ix_in_router_manager_room_id': needed in a foreign key constraint")
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "app-migrate.py", line 53, in
manager.run()
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/flask_script/__init__.py", line 417, in run
result = self.handle(argv[0], argv[1:])
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/flask_script/__init__.py", line 386, in handle
res = handle(*args, **config)
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/flask_script/commands.py", line 216, in __call__
return self.run(*args, **kwargs)
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/flask_migrate/__init__.py", line 95, in wrapped
f(*args, **kwargs)
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/flask_migrate/__init__.py", line 280, in upgrade
command.upgrade(config, revision, sql=sql, tag=tag)
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/alembic/command.py", line 254, in upgrade
script.run_env()
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/alembic/script/base.py", line 427, in run_env
util.load_python_file(self.dir, 'env.py')
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/alembic/util/pyfiles.py", line 81, in load_python_file
module = load_module_py(module_id, path)
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/alembic/util/compat.py", line 82, in load_module_py
spec.loader.exec_module(module)
File "", line 728, in exec_module
File "", line 219, in _call_with_frames_removed
File "migrations/env.py", line 87, in
run_migrations_online()
File "migrations/env.py", line 80, in run_migrations_online
context.run_migrations()
File "", line 8, in run_migrations
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/alembic/runtime/environment.py", line 836, in run_migrations
self.get_context().run_migrations(**kw)
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/alembic/runtime/migration.py", line 330, in run_migrations
step.migration_fn(**kw)
File "/srv/web_develop/vpp_agent_dev/agent/source/migrations/versions/8400cd3396af_.py", line 21, in upgrade
op.drop_index('ix_in_router_manager_room_id', table_name='in_router_manager')
File "", line 8, in drop_index
File "", line 3, in drop_index
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/alembic/operations/ops.py", line 964, in drop_index
return operations.invoke(op)
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/alembic/operations/base.py", line 319, in invoke
return fn(self, operation)
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/alembic/operations/toimpl.py", line 94, in drop_index
operation.to_index(operations.migration_context)
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/alembic/ddl/impl.py", line 204, in drop_index
self._exec(schema.DropIndex(index))
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/alembic/ddl/impl.py", line 115, in _exec
return conn.execute(construct, *multiparams, **params)
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/sqlalchemy/engine/base.py", line 948, in execute
return meth(self, multiparams, params)
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/sqlalchemy/sql/ddl.py", line 68, in _execute_on_connection
return connection._execute_ddl(self, multiparams, params)
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/sqlalchemy/engine/base.py", line 1009, in _execute_ddl
compiled
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/sqlalchemy/engine/base.py", line 1200, in _execute_context
context)
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/sqlalchemy/engine/base.py", line 1413, in _handle_dbapi_exception
exc_info
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/sqlalchemy/util/compat.py", line 265, in raise_from_cause
reraise(type(exception), exception, tb=exc_tb, cause=cause)
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/sqlalchemy/util/compat.py", line 248, in reraise
raise value.with_traceback(tb)
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/sqlalchemy/engine/base.py", line 1193, in _execute_context
context)
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/sqlalchemy/engine/default.py", line 509, in do_execute
cursor.execute(statement, parameters)
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/pymysql/cursors.py", line 170, in execute
result = self._query(query)
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/pymysql/cursors.py", line 328, in _query
conn.query(q)
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/pymysql/connections.py", line 516, in query
self._affected_rows = self._read_query_result(unbuffered=unbuffered)
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/pymysql/connections.py", line 727, in _read_query_result
result.read()
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/pymysql/connections.py", line 1066, in read
first_packet = self.connection._read_packet()
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/pymysql/connections.py", line 683, in _read_packet
packet.check_error()
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/pymysql/protocol.py", line 220, in check_error
err.raise_mysql_exception(self._data)
File "/srv/vpp_agent_venv3.7/lib/python3.7/site-packages/pymysql/err.py", line 109, in raise_mysql_exception
raise errorclass(errno, errval)
sqlalchemy.exc.InternalError: (pymysql.err.InternalError) (1553, "Cannot drop index 'ix_in_router_manager_room_id': needed in a foreign key constraint") [SQL: '\nDROP INDEX ix_in_router_manager_room_id ON in_router_manager'] (Background on this error at: http://sqlalche.me/e/2j85)
(vpp_agent_venv3.7) [root@localhost source]#
修改后，再次migrate就会报：ERROR [root] Error: Target database is not up to date.
(vpp_agent_venv3.7) [root@localhost source]# python app-migrate.py db migrate
INFO [alembic.runtime.migration] Context impl MySQLImpl.
INFO [alembic.runtime.migration] Will assume non-transactional DDL.
ERROR [root] Error: Target database is not up to date.查看当前的tag和之前的
(vpp_agent_venv3.7) [root@localhost source]# python app-migrate.py db current
INFO [alembic.runtime.migration] Context impl MySQLImpl.
INFO [alembic.runtime.migration] Will assume non-transactional DDL.
48a794328fe9
(vpp_agent_venv3.7) [root@localhost source]# python app-migrate.py db heads
8400cd3396af (head)恢复之前heads的版本
(vpp_agent_venv3.7) [root@localhost source]# python app-migrate.py db stamp heads
INFO [alembic.runtime.migration] Context impl MySQLImpl.
INFO [alembic.runtime.migration] Will assume non-transactional DDL.
INFO [alembic.runtime.migration] Running stamp_revision 48a794328fe9 -> 9573295ce506
(vpp_agent_venv3.7) [root@localhost source]# python app-migrate.py db current
INFO [alembic.runtime.migration] Context impl MySQLImpl.
INFO [alembic.runtime.migration] Will assume non-transactional DDL.
9573295ce506 (head)重新migrate和upgrade
(vpp_agent_venv3.7) [root@localhost source]# python app-migrate.py db migrate
INFO [alembic.runtime.migration] Context impl MySQLImpl.
INFO [alembic.runtime.migration] Will assume non-transactional DDL.
INFO [alembic.autogenerate.compare] Detected removed foreign key (room_id)(id) on table in_router_manager
INFO [alembic.autogenerate.compare] Detected added foreign key (room_id)(id) on table in_router_manager
Generating /srv/web_develop/vpp_agent_dev/agent/source/migrations/versions/ad397c57d1b1_.py ... done
(vpp_agent_venv3.7) [root@localhost source]# python app-migrate.py db upgrade
INFO [alembic.runtime.migration] Context impl MySQLImpl.
INFO [alembic.runtime.migration] Will assume non-transactional DDL.
INFO [alembic.runtime.migration] Running upgrade 9573295ce506 -> ad397c57d1b1, empty message