SQLAlchemy 做migration的時候 ValueError: too many values to unpack

 

 

我在做數據庫遷移的時候，使用sqlalchemy，出現一個問題

Traceback (most recent call last):
  File "/Volumes/Spano/Dropbox/Dropbox/eclipse-workspace/CAUDLE/src/caudle/caudle/db_migrate.py", line 11, in <module>
    script = api.make_update_script_for_model(SQLALCHEMY_DATABASE_URI, SQLALCHEMY_MIGRATE_REPO, tmp_module.meta, db.metadata)
  File "<string>", line 2, in make_update_script_for_model
  File "/Users/johncaine/anaconda/lib/python2.7/site-packages/migrate/versioning/util/__init__.py", line 89, in catch_known_errors
    return f(*a, **kw)
  File "<string>", line 2, in make_update_script_for_model
  File "/Users/johncaine/anaconda/lib/python2.7/site-packages/migrate/versioning/util/__init__.py", line 159, in with_engine
    return f(*a, **kw)
  File "/Users/johncaine/anaconda/lib/python2.7/site-packages/migrate/versioning/api.py", line 321, in make_update_script_for_model
    engine, oldmodel, model, repository, **opts)
  File "/Users/johncaine/anaconda/lib/python2.7/site-packages/migrate/versioning/script/py.py", line 69, in make_update_script_for_model
    genmodel.ModelGenerator(diff,engine).genB2AMigration()
  File "/Users/johncaine/anaconda/lib/python2.7/site-packages/migrate/versioning/genmodel.py", line 197, in genB2AMigration
    for modelCol, databaseCol, modelDecl, databaseDecl in td.columns_different:
ValueError: too many values to unpack

　　

各種google后發現了原因，是在http://stackoverflow.com/questions/20250901/python-sql-alchemy-migrate-valueerror-too-many-values-to-unpack-when-migrat找到的答案，非常感謝stackoverflow的大神，

就是在modle.py中定義數據表的時候使用了Boolean，當我把db.Boolean都換成了db.SmallInteger就解決了問題，非常感謝啊。。。另外，發現在定義的時候Boolean是不分大小寫的，所以記得完全更換，就不會影響遷移了，太開心啦~~~

boolean對應的是tinyint，smallinteger對應的是smallint，，，當遷移之后，mysql中的tinyint不會轉換為smallint，但是不會影響使用。

 

使用的sqlalchemy是0.7.9，sqlalchemy-migrate是0.7.2

 

最后附一個學習sqlalchemy的地址，非常好：http://blog.miguelgrinberg.com/post/the-flask-mega-tutorial-part-iv-database