ORM attributed updated but not reflected in queries.

[Tim Henderson]

This is for SQL Alchemy 1.0.0b1 - 1.0.0 final. Issue is not present in 0.9.9

The attached file reproduces the bug. It will print "passed test" if the bug is not present or "failed test" if the bug is present. You must first setup the database credentials in the test file.

The bug:

I create a new ORM object and then override a foreign key manually. I then add the row and commit it. In prior versions of SQLAlchemy (for instance 0.9.9) this will cause an integrity error as the child row is not present. In 1.0.0 the wrong attribute is rendered in the SQL insert query. This means no integrity error occurs and the insert succeeds. However, it has inserted the wrong data.

Enivronment:

• pypy: 2.5.1 (cpython 2.7.9 compat)
• SQLAlchemy: 1.0.0 (works in 0.9.9)
• MySQL: 5.6

[Mike Bayer]

issue #3060 changed this behavior.

[Mike Bayer]

Alex Grönholm made up a more succinct test case:

import sqlalchemy as sa

from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import Session

Base = declarative_base()


class A(Base):
    __tablename__ = 'table_a'
    __table_args__ = {'mysql_engine':'InnoDB'}

    id = sa.Column(sa.String(20), primary_key=True)


class B(Base):
    __tablename__ = 'table_b'
    __table_args__ = {'mysql_engine':'InnoDB'}

    id = sa.Column(sa.Integer, primary_key=True)
    a_id = sa.Column(sa.String(20), sa.ForeignKey('table_a.id'))
    a = sa.orm.relationship(A, primaryjoin=a_id == A.id)


engine = sa.create_engine("postgresql:///testdb")
Base.metadata.create_all(engine)
session = Session(engine)

try:
    b = B()
    b.a = None
    b.a_id = 'arbitrary_key'
    session.add(b)
    session.flush()
except sa.exc.IntegrityError:
    print "passed test"
else:
    print "failed test"
finally:
    Base.metadata.drop_all(engine)

[Mike Bayer]

• add documentation describing the behavioral change in relationship assignments that we would see from #3060; fixes #3369

→ <<cset bd61e7a32870>>