CODEWITHSUNDEEP
pythonunicodesqlalchemyinsertion
Raiders
Raiders

Reputation: 191

Proper Way to Insert Strings to a SQLAlchemy Unicode Column

I have a SQLAlchemy model with a Unicode column. I sometimes insert unicode values to it (u'Value'), but also sometimes insert ASCII strings. What is the best way to go about this? When I insert ASCII strings with special characters I get this warning: 

SAWarning: Unicode type received non-unicode bind param value ...

How do I avoid this? What is the proper way to insert my different types of strings?

Upvotes: 14

Views: 8092

Answers (2)

PersianGulf
PersianGulf

Reputation: 2935

You should define your table class and constructor as such:

class User(declarative_base()):
    _tablename__ = 'user'
    name = Column(Unicode(200, convert_unicode=False))
    textfield = Column(UnicodeText(convert_unicode=False))

user = Table('user', MetaData(),
Column('name', Unicode(200, convert_unicode=False), nullable=False),
Column('textfield', UnicodeText(convert_unicode=False), nullable=False),
)

Of course, you should not forget to attach URI+"charset=utf8" for create_engine function

Upvotes: 0

Denis Otkidach
Denis Otkidach

Reputation: 33200

Thre are several options:

  1. Disable all SQLAlchemy warnings with warnings.simplefilter('ignore', sqlalchemy.exc.SAWarning).
  2. Disable only this warning with more specific filter spec by module and lineno or message, e.g. warnings.filterwarnings('ignore', '^Unicode type received non-unicode bind param value', sqlalchemy.exc.SAWarning).
  3. Use String(convert_unicode=True) instead of Unicode type.
  4. Rethink the problem and change your code to use unicode even for ASCII strings.

Upvotes: 5

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