Flask SQLAlchemy autoincrement without using primary key

Question

I would like to use the autoincrement option on the field id in SQLAlchemy without setting the column as a primary key. Something like that:

class CaseModel(db.Model):
__tablename__ = 'case'

unique_id = db.Column(UUID(as_uuid=True), unique=True, nullable=False, primary_key=True)
id = db.Column(db.Integer(), autoincrement=True)

Is that possible?

score 0 · Answer 1 · answered Nov 14 '19 at 11:21

0

You can do it using hybrid property:

class CaseModel(db.Model):
    __tablename__ = 'case'
    CURRENT_ID_VALUE = 1

    unique_id = db.Column(UUID(as_uuid=True), unique=True, nullable=False, primary_key=True)
    _id = db.Column(db.Integer())

    @hybrid_property
    def id(self):
        return self._id

    @id.setter
    def id(self, _):
        self._id = CaseModel.CURRENT_ID_VALUE
        CaseModel.CURRENT_ID_VALUE += 1

answered Nov 14 '19 at 11:21

SampleText2k77

198
7

Thanks for the quick reply. I tried your suggestion but it did not work. – Y.kh Nov 14 '19 at 11:32
Well, I haven't tested this solution, you can try to make CURRENT_ID_VALUE global or store it somewhere and use it in your Model – SampleText2k77 Nov 14 '19 at 13:48
The main idea is to use hybrid property for any custom behavior on get/set operations – SampleText2k77 Nov 14 '19 at 13:49

Flask SQLAlchemy autoincrement without using primary key

1 Answers1