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flask-sqlalchemy inheritance

Ugly Unicorn answered on July 6, 2022 Popularity 4/10 Helpfulness 2/10

answer flask-sqlalchemy inheritance

related flask sqlalchemy single table inheritance

flask-sqlalchemy inheritance

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import sqlalchemy as sa
from flask import Flask

from flask_sqlalchemy import SQLAlchemy

app = Flask(__name__)
app.config['SQLALCHEMY_ECHO'] = True
db = SQLAlchemy(app)


class BaseModel(db.Model):
    __abstract__ = True
    id = sa.Column(sa.Integer, primary_key=True)


class A(BaseModel):
    a_name = sa.Column(sa.String)
    a_type = sa.Column(sa.String)
    __mapper_args__ = {
        'polymorphic_on': a_type,
        'polymorphic_identity': 'a',
    }


class B(BaseModel):
    b_name = sa.Column(sa.String)
    b_type = sa.Column(sa.String)
    __mapper_args__ = {
        'polymorphic_identity': 'b',
        'polymorphic_on': b_type
    }


class Inheritance(A, B):
    a_id = sa.Column(sa.ForeignKey(A.id), primary_key=True)
    b_id = sa.Column(sa.ForeignKey(B.id), primary_key=True)
    name = sa.Column(sa.String)


db.create_all()
db.session.add_all((A(), B()))
db.session.commit()
db.session.add(Inheritance(a_id=1, b_id=1))
db.session.commit()

Popularity 4/10 Helpfulness 2/10 Language python

Source: Grepper

Tags: flask-sqlalchemy inheritance python

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Contributed on Jul 12 2022

Ugly Unicorn

0 Answers Avg Quality 2/10

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flask sqlalchemy single table inheritance

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class User(db.Model):
    __tablename__ = 'tbl_user'
    type = db.Column(db.String(32)) 
    ...
    __mapper_args__ = {
        'polymorphic_identity': 'user',
        'polymorphic_on': type,
    }  # remove with_polymorphic

class Tourist(User):
    __tablename__ = None  # Add table name to be None
    __mapper_args__ = {
        'polymorphic_identity': 'tourist'
    }
    ...

class Guide(User):
    __tablename__ = None  # Add table name to be None
    __mapper_args__ = {
        'polymorphic_identity': 'guide'
    }
    ...

Popularity 4/10 Helpfulness 1/10 Language sql

Source: stackoverflow.com

Tags: sql single-table-inheritance flask-sqlalchemy

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Contributed on Jul 06 2022

Mohammed BAIRAQ

0 Answers Avg Quality 2/10

flask-sqlalchemy inheritance

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