How to set ManyToOne relationship in Flask- SQL alchemy?

KbiR 0
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I am new to Flask and SQLalchmey. I am trying to crate two tables and establish a manytoone relationship between them.

Here is what I did.

table_hub

      class Hub(db.Model):
          __tablename__ = 'hub'

          id = db.Column(db.Integer, primary_key=True)
          name = db.Column(db.String(),nullable=False,unique=True)

tbl_vehicle

      class vehileMaster(db.Model):
          __tablename__ = 'res.vehicle'

          id = db.Column(db.Integer, primary_key=True)
          name = db.Column(db.String, nullable=False)
          hub_id = db.Column(db.Integer,db.ForeignKey('hub.id'))
          hub = db.relationship('Hub')

Here is what I need to achieve,

  1. while creating a new vehicle in table res.vehicle I need to choose a hub from the list of hubs.

I don't know whether what i already did is correct or not.

sqlalchemy flask-sqlalchemy flask
1 Answers

The standard way of implementing a foreign key relationship would be:

class Hub(db.Model):
    __tablename__ = 'hub'

    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(), nullable=False,unique=True)
    vehicles = db.relationship('res.vehicle', backref='hub', lazy=True)


class vehicleMaster(db.Model):
    __tablename__ = 'res.vehicle'

    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String, nullable=False)
    hub_id = db.Column(db.Integer, db.ForeignKey('hub.id'))
Robin Uphoff0
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