I getting this error:
sqlalchemy.exc.NoReferencedColumnError: Could not initialize target column for ForeignKey 'title.id' on table 'post': table 'title' has no column named 'id'
when I remove these two line I'm not getting any error:
head_id = Column(Integer, ForeignKey('title.id'))
head = relationship('Title', backref='post')
What I'm doing wrong with relationship and foreignKey?
My code main.py
from flask import Flask, render_template, request, redirect, url_for
import datetime
from sqlalchemy.orm import sessionmaker
from sqlalchemy import Column, String, Integer, create_engine, ForeignKey
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import relationship
# flask documentation >> https://flask.palletsprojects.com/en/1.1.x/quickstart/
app = Flask(__name__, template_folder='template', static_folder='static')
Base = declarative_base()
date = datetime.datetime.strftime(datetime.datetime.now(), '%d-%b-%Y')
engine = create_engine('mysql://root:@localhost/flask')
Base.metadata.create_all = engine
database = sessionmaker(bind=engine)
session = database()
class contacts(Base):
__tablename__='contacts'
id = Column('No.', Integer, primary_key=True)
name = Column('Name', String(15), nullable=True)
email = Column('Email', String(20), nullable=True)
phone = Column('Phone', String(14), nullable=True)
message = Column('Message', String(100))
date = Column('Date', String, default=date)
def __repr__(self):
return '<contacts(Name=%s, Email=%s, Phone=%s, Message=%s, Date=%s)>' % (
self.name, self.email, self.phone, self.message, self.date)
class Title(Base):
__tablename__='title'
id = Column('No', Integer, primary_key=True)
title = Column('Title', String, nullable=False)
date = Column('Date', String, nullable=False, default=date)
def __repr__(self):
return '<head(Title=%s, Date=%s)>' % (self.title, self.date)
class Post(Base):
__tablename__='post'
id = Column('No', Integer, primary_key=True)
post = Column('Post', String, nullable=False)
head_id = Column(Integer, ForeignKey('title.id'))
head = relationship('Title', backref='post')
def __repr__(self):
return '<post(Post=%s)>' % self.post
@app.route('/')
def index():
data = session.query(Post).all()
return render_template('index.html', data=data)
# router for contact ['post' and 'get'] method
@app.route('/contact', methods=['POST', 'GET'])
def contact():
# if 'contact.html' form method is 'post' this will run , otherwise not
if request.method=='POST':
# getting value from your 'contact.html' page
name = request.form['name']
email = request.form['email']
phone = request.form['phone']
message = request.form['message']
# attempt to adding value in database
try:
# commit to adding value in database
value = contacts(name=name, email=email, phone=phone, message=message)
session.add(value)
session.commit()
session.close()
# redirect home page
return redirect(url_for('index'))
# any problem while adding value in database
except Exception as e:
print(e)
else:
# not request for 'POST'
return render_template('contact.html')
# These are all route points (end points)
@app.route('/post')
def post():
return render_template('post.html')
@app.route('/about')
def about():
return render_template('about.html')
if __name__ == '__main__':
# run application, and 'debug'= It'll auto configure you changes (you don't need you restart you app again and again'
app.run(debug=True)
How can I create relationship b/w Title and Post?