How to find the offending attribute with a sqlalchemy IntegrityError

问题

I have a very simple SqlAlchemy model

class User(Base):
    """ The SQLAlchemy declarative model class for a User object. """
    __tablename__ = 'users'
    id = Column(Integer, primary_key=True)
    phone = Column(String, unique=True)
    email = Column(String, unique=True)

When inserting a new User, an IntegrityError could occur if the email or phone is a duplicate.

Is there any way to detect which of the columns was violating the integrity error? Or is the only way to do a separate query to see or a value is present?

回答1:

You can use the below way to get the underlying code, message, and format the message accordingly.

except exc.IntegrityError as e:
       errorInfo = e.orig.args
       print(errorInfo[0])  #This will give you error code
       print(errorInfo[1])  #This will give you error message

BTW, you have to import exc from sqlalchemy: from sqlalchemy import exc Let me know if you need any other info. I can try it out.

For more info on sqlalchemy exc, please find the code: https://github.com/zzzeek/sqlalchemy/blob/master/lib/sqlalchemy/exc.py

回答2:

There's no clean way to do this unfortunately but I use the orig attribute on the IntegrityError and the parse module:

try:
    db.session.add(user)
    db.session.commit()
except IntegrityError, e:
    dupe_field = parse('duplicate key value violates unique constraint "{constraint}"\nDETAIL:  Key ({field})=({input}) already exists.\n', str(e.orig))["field"]

This may not be the only error string IntegrityError throws and it could change in future updates to SQLAlchemy so its not ideal

回答3:

I normally use a try catch for this.

try:
    session.commit()
catch:   
str(sys.exc_info()[0]) + " \nDESCRIPTION:  "+ str(sys.exc_info()[1]) + "\n" + str(sys.exc_info()[2])

When I encounter an integrity error, I get the following message and I skip that particular transcation and continue with the rest of them

DESCRIPTION:  (IntegrityError) duplicate key value violates unique constraint "test_code"
DETAIL:  Key (test_code)=(5342) already exists.
'INSERT INTO test_table (pk, test_code, test_name) VALUES (%(pk)s, %(test_code)s, %(test_name)s)' { 'pk': '1', 'test_code': '5342', 'test_name': 'test' }

来源：https://stackoverflow.com/questions/11313490/how-to-find-the-offending-attribute-with-a-sqlalchemy-integrityerror

标签

python

sqlalchemy

integrity