CODEWITHSUNDEEP
pythonsqliteflask-sqlalchemy
Abhishek Ghosh
Abhishek Ghosh

Reputation: 2706

Flask SqlAlchemy : Records not displayed

Here is my code : 

from flask import Flask
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker
from database_setup import Base, Restaurant, MenuItem

app = Flask(__name__)

engine = create_engine('sqlite:///restaurantmenu.db')
Base.metadata.bind = engine

DBSession = sessionmaker(bind=engine)
session = DBSession()


@app.route('/')
@app.route('/restaurants/<int:restaurant_id>/')
def restaurantMenu(restaurant_id):
    restaurant = session.query(Restaurant).filter_by(id=restaurant_id).one()
    items = session.query(MenuItem).filter_by(restaurant_id=restaurant.id)
    output = ''
    for i in items:
        output += i.name
        output += '</br>'
        output += i.price
        output += '</br>'
        output += i.description
        output += '</br>'
        output += '</br>'
    return output

if __name__ == '__main__':
    app.debug = True
    app.run(host='0.0.0.0', port=5000)

I run the file by entering the following URL :

localhost:5000/restaurants/2

And all I get is a blank page. I don't get any kind of error in my GitBash or browser or anywhere else.

I ran this simple code :

from flask import Flask
app = Flask(__name__)


@app.route('/')
@app.route('/hello')
def HelloWorld():
    return "Hello World"

if __name__ == '__main__':
    app.debug = True
    app.run(host='0.0.0.0', port=5000)

And this runs perfectly. What wrong am I doing ?

EDIT : 1

Tried to debug the code and noticed that the code doesn't enter the for i in items: loop.

@app.route('/')
@app.route('/hello')
def restaurantMenu():
    restaurant = session.query(Restaurant).first()
    items = session.query(MenuItem).filter_by(restaurant_id = restaurant.id)
    output = ''
    print restaurant.name
    print restaurant.id

    if not items :
        print "No menu items!"
    else:
        print "There are menu items!"
        for i in items:
            print "In items loop!"
            output += i.name
            output += '<br>'
    return output + "Hello"

enter image description here

Upvotes: 0

Views: 423

Answers (1)

Ja8zyjits
Ja8zyjits

Reputation: 1503

Basically you need the all() function at your items. You are querying properly but you are not fetching the results.

so your code will be like this

@app.route('/')
@app.route('/restaurants/<int:restaurant_id>/')
def restaurantMenu(restaurant_id):
    restaurant = session.query(Restaurant).filter_by(id=restaurant_id).one()
    items = session.query(MenuItem).filter_by(restaurant_id=restaurant.id).all()
    output = ''
    for i in items:
        output += i.name
        output += '</br>'
        output += i.price
        output += '</br>'
        output += i.description
        output += '</br>'
        output += '</br>'
    return output

if __name__ == '__main__':
    app.debug = True
    app.run(host='0.0.0.0', port=5000)

Now it will depend on the entries in your db, if you have any or else it will return an empty []. So if you have the results, you can print and check or loop and render it to your templates.

This should fix your issue

Upvotes: 1

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