SQLalchemy AttributeError: 'str' object has no attribute '_sa_instance_state'

Question

I\'m trying to add an item to my database with SQLAlchemy + Python, but keep getting an error.

My database_setup.py:

class company(Base):
    __table         


        

Answer 1

from flask import Flask
from flask import request,redirect,render_template
from flask_sqlalchemy import SQLAlchemy

app=Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///students1.sqlite3'
db=SQLAlchemy(app)

class Categ(db.Model):
    id=db.Column(db.Integer,primary_key=True)
    name=db.Column(db.String(100))
    product=db.relationship('Product',backref='owner',lazy=True)

class Product(db.Model):
    id=db.Column(db.Integer,primary_key=True)
    pname=db.Column(db.String(100))
    price=db.Column(db.Integer)
    categ_id=db.Column(db.Integer,db.ForeignKey('categ.id'))

@app.route('/')
def home():
    return 'home'

@app.route('/post',methods=['POST','GET'])
def Productform():
    ob=Categ.query.all()
    if request.method=='POST':
        owner=request.form['ca']
        user = Categ.query.filter_by(name=owner).first()

        user=Product(pname=request.form['pname'],price=request.form['price'],owner=user)
        db.session.add(user)
        db.session.commit()

        return 'submit'

    return render_template('product.html',ob=ob)



@app.route('/categ',methods=['POST','GET'])
def Categoryform():
    if request.method=='POST':
        user=Categ(name=request.form['cname'])
        db.session.add(user)
        db.session.commit()

        return 'submit'

    return render_template('categ.html')


if __name__ == '__main__':
   app.run(debug=True)
   db.create_all()