How can i add a user into the Wallet Table when a user is been created in the User table am plaining on using a event listen on the User table but its seems not working at all.
def User(db.Model):
id = db.Column(db.Integer, primary_key=True)
username = db.Column(db.String)
sponsor_referral_id = db.Column(db.String)
def Wallet(db.Model):
id = db.Column(db.Integer, primary_key=True)
username = db.Column(db.String)
wallet_1 = db.Column(db.Float, default=0.0)
wallet_2 = db.Column(db.Float, default=0.0)
I tried this:
@event.listens_for(User, "after_insert")
def create_wallet(mapper, connection, target):
target.session.add(Wallet(username=target.username))
Which produced nothing when a user i been added into the User table.
I Need help on how to work on this.
Maybe I'm wrong 🤔... But results may not be consistent when you using after_insert + session.add(). I think in you case better to use after_flush. Because flush() passes a series of operations (insert, update, delete) in one transaction. So you can add a new operation after flush but before commit:
from flask import Flask, jsonify
from flask_sqlalchemy import SQLAlchemy
from sqlalchemy import event
app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'postgresql://...blablalba...'
app.config['SQLALCHEMY_ECHO'] = True # let's check queries
db = SQLAlchemy(app)
class User(db.Model):
id = db.Column(db.Integer, primary_key=True)
username = db.Column(db.String)
sponsor_referral_id = db.Column(db.String)
class Wallet(db.Model):
id = db.Column(db.Integer, primary_key=True)
username = db.Column(db.String)
wallet_1 = db.Column(db.Float, default=0.0)
wallet_2 = db.Column(db.Float, default=0.0)
@event.listens_for(db.session, 'after_flush')
def example(session, instance):
# save new Wallet record if new User
for rec in session.new:
if isinstance(rec, User):
session.add(Wallet(username=rec.username))
@app.route('/')
def test():
# create a user and check for updates
db.session.add(User(username='test', sponsor_referral_id='test'))
db.session.commit()
user1 = User.query.first()
user1.username = 'new name'
db.session.commit()
# create one more user
db.session.add(User(username='test2', sponsor_referral_id='test2'))
db.session.commit()
return jsonify({'wallets': len(Wallet.query.all()), 'users': len(User.query.all())})
db.create_all()
Run server, open http://localhost:5000/ and let's look at logs:
2021-07-16 17:48:33,992 INFO sqlalchemy.engine.Engine BEGIN (implicit)
2021-07-16 17:48:33,994 INFO sqlalchemy.engine.Engine INSERT INTO "user" (username, sponsor_referral_id) VALUES (%(username)s, %(sponsor_referral_id)s) RETURNING "user".id
2021-07-16 17:48:33,994 INFO sqlalchemy.engine.Engine [generated in 0.00023s] {'username': 'test', 'sponsor_referral_id': 'test'}
2021-07-16 17:48:33,997 INFO sqlalchemy.engine.Engine INSERT INTO wallet (username, wallet_1, wallet_2) VALUES (%(username)s, %(wallet_1)s, %(wallet_2)s) RETURNING wallet.id
2021-07-16 17:48:33,998 INFO sqlalchemy.engine.Engine [generated in 0.00030s] {'username': 'test', 'wallet_1': 0.0, 'wallet_2': 0.0}
2021-07-16 17:48:33,999 INFO sqlalchemy.engine.Engine COMMIT
2021-07-16 17:48:34,004 INFO sqlalchemy.engine.Engine BEGIN (implicit)
2021-07-16 17:48:34,006 INFO sqlalchemy.engine.Engine SELECT "user".id AS user_id, "user".username AS user_username, "user".sponsor_referral_id AS user_sponsor_referral_id
FROM "user"
LIMIT %(param_1)s
2021-07-16 17:48:34,007 INFO sqlalchemy.engine.Engine [generated in 0.00026s] {'param_1': 1}
2021-07-16 17:48:34,010 INFO sqlalchemy.engine.Engine UPDATE "user" SET username=%(username)s WHERE "user".id = %(user_id)s
2021-07-16 17:48:34,010 INFO sqlalchemy.engine.Engine [generated in 0.00020s] {'username': 'new name', 'user_id': 1}
2021-07-16 17:48:34,010 INFO sqlalchemy.engine.Engine COMMIT
2021-07-16 17:48:34,012 INFO sqlalchemy.engine.Engine BEGIN (implicit)
2021-07-16 17:48:34,012 INFO sqlalchemy.engine.Engine INSERT INTO "user" (username, sponsor_referral_id) VALUES (%(username)s, %(sponsor_referral_id)s) RETURNING "user".id
2021-07-16 17:48:34,013 INFO sqlalchemy.engine.Engine [cached since 0.01892s ago] {'username': 'test2', 'sponsor_referral_id': 'test2'}
2021-07-16 17:48:34,014 INFO sqlalchemy.engine.Engine INSERT INTO wallet (username, wallet_1, wallet_2) VALUES (%(username)s, %(wallet_1)s, %(wallet_2)s) RETURNING wallet.id
2021-07-16 17:48:34,014 INFO sqlalchemy.engine.Engine [cached since 0.01685s ago] {'username': 'test2', 'wallet_1': 0.0, 'wallet_2': 0.0}
2021-07-16 17:48:34,015 INFO sqlalchemy.engine.Engine COMMIT
Looks like what you need.