環境描述：

在github上面 下載了一個flask專案之後

 python manage.py db upgrade
Traceback (most recent call last):
  File "manage.py", line 17, in <module>
    manager.run()
  File "C:\Python27\lib\site-packages\flask_script\__init__.py", line 412, in run
    result = self.handle(sys.argv[0], sys.argv[1:])
  File "C:\Python
 
27\lib\site-packages\flask_script\__init__.py", line 383, in handle
    res = handle(*args, **config)
  File "C:\Python27\lib\site-packages\flask_script\commands.py", line 216, in __call__
    return self.run(*args, **kwargs)
  File "C:\Python27\lib\site-packages\flask_migrate\__init__.py", line 235, in upgrade
    command.upgrade(config, revision, sql=sql, tag=tag)
  File "C:\Python
 
27\lib\site-packages\alembic\command.py", line 174, in upgrade
    script.run_env()
  File "C:\Python27\lib\site-packages\alembic\script\base.py", line 397, in run_env
    util.load_python_file(self.dir, 'env.py')
  File "C:\Python27\lib\site-packages\alembic\util\pyfiles.py", line 93, in load_python_file
    module = load_module_py(module_id, path)
  File "C:\Python
 
27\lib\site-packages\alembic\util\compat.py", line 79, in load_module_py
    mod = imp.load_source(module_id, path, fp)
  File "migrations\env.py", line 87, in <module>
    run_migrations_online()
  File "migrations\env.py", line 70, in run_migrations_online
    poolclass=pool.NullPool)
  File "C:\Python27\lib\site-packages\sqlalchemy\engine\__init__.py", line 427, in engine_from_config
    return create_engine(url, **options)
  File "C:\Python27\lib\site-packages\sqlalchemy\engine\__init__.py", line 386, in create_engine
    return strategy.create(*args, **kwargs)
  File "C:\Python27\lib\site-packages\sqlalchemy\engine\strategies.py", line 75, in create
    dbapi = dialect_cls.dbapi(**dbapi_args)
  File "C:\Python27\lib\site-packages\sqlalchemy\dialects\mysql\mysqldb.py", line 92, in dbapi
    return __import__('MySQLdb')
ImportError: No module named MySQLdb

python manage.py db upgrade 執行報錯

在網上搜索瞭解決方案如下：

1. 安裝PyMySQL

$ pip install PyMySQL
Collecting PyMySQL
  Downloading PyMySQL-0.7.11-py2.py3-none-any.whl (78kB)
Installing collected packages: PyMySQL
Successfully installed PyMySQL-0.7.11

2 .列表內容

. 在專案的init.py中新增

import pymysql
pymysql.install_as_MySQLdb()

3.成功執行python manage.py db upgrade

$ python manage.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  -> 83fd966f85c2, empty message
INFO  [alembic.runtime.migration] Running upgrade 83fd966f85c2 -> fb71a8f269d8, empty message
INFO  [alembic.runtime.migration] Running upgrade fb71a8f269d8 -> 59e062953154, empty message
INFO  [alembic.runtime.migration] Running upgrade 59e062953154 -> 39c00b1bb40c, empty message
INFO  [alembic.runtime.migration] Running upgrade 39c00b1bb40c -> 2b5859bebcf1, empty message
INFO  [alembic.runtime.migration] Running upgrade 2b5859bebcf1 -> 8e75c327e44f, empty message
INFO  [alembic.runtime.migration] Running upgrade 8e75c327e44f -> c02c89e63a71, empty message
INFO  [alembic.runtime.migration] Running upgrade c02c89e63a71 -> 62582649ce6e, empty message
INFO  [alembic.runtime.migration] Running upgrade 62582649ce6e -> 2a798695be49, empty message
INFO  [alembic.runtime.migration] Running upgrade 2a798695be49 -> 3420f22521af, empty message
INFO  [alembic.runtime.migration] Running upgrade 3420f22521af -> dfad1f2acb22, empty message