Flask-SQLAlchemy session.rollback不起作用

Question

I´m developing an API with FLASK and I´m using FLASK-SQALCHEMY.

Well, when the api throws some exception, I try to rollback the session.

My Code

def create_user():
    user = User()
    db.session.add(user)
    db.session.flush()
    return user

try:
    new_user = create_user()
    print('x' + 2) # force error
    db.session.commit()
except Exception as error:
    db.session.rollback()
    raise

My requirements (Python 3.6.3 & MySQL 5.7):

SQLAlchemy==1.2.2
astroid==1.6.0
flask==0.12.2
flask-login==0.4.1
Flask-Migrate==2.1.1
flask-script==2.0.6
flask-sqlalchemy==2.3.2
flask-validator==1.2.3
isort==4.2.15
pygelf==0.3.3
pylint==1.8.1
PyMySQL==0.7.11
pytest==3.3.1
Werkzeug==0.13

Answer 1

From the docs :

The FLUSH statement causes an implicit commit

Remove the db.session.flush() and it should work as expected.