Background: I am building a Flask App and I have stored my data into a postgresql database and within a JSON column type.
Task: In my view functions, I would like to order a database query by {Key:Value} from JSON column
Accomplished: I have been successful in performing this query at the psql command-line by using the following command for example:
select * from target where cast(product->>'profit' as float) > 100 order by cast(product->>'salesrank' as integer) asc;
Problem: I can not replicate this query in my code (see code for Model below in Extra Info Section)
from app import app, db
from models import Target
data = Target.query.order_by(Target.product['salesrank'])
Error received - ProgrammingError: (ProgrammingError) could not identify an ordering operator for type json LINE 2: FROM target ORDER BY target.product -> 'salesrank' ^ HINT: Use an explicit ordering operator or modify the query. 'SELECT target.id AS target_id, target.store AS target_store, target.product AS target_product, target.asin AS target_asin, target.date AS target_date \nFROM target ORDER BY target.product -> %(product_1)s \n LIMIT %(param_1)s' {'product_1': 'salesrank', 'param_1': 1}
Extra Info My Target model was set up as such:
#models.py
from app import db
from sqlalchemy.dialects.postgresql import JSON
import datetime
class Target(db.Model):
__tablename__ = 'target'
id = db.Column(db.Integer)
store = db.Column(db.String())
product = db.Column(JSON)
asin = db.Column(db.String(), primary_key=True)
date = db.Column(db.DateTime, default=datetime.datetime.utcnow())
My App.py file where I define Flask and Sqlalchemy
from flask import Flask
import os
from flask.ext.sqlalchemy import SQLAlchemy
from flask_bootstrap import Bootstrap
app = Flask(__name__)
app.config.from_object(os.environ['APP_SETTINGS'])
db = SQLAlchemy(app)
Bootstrap(app)
import views
from app import app
from models import Result
if __name__ == '__main__':
app.run(host='192.168.1.5', port=5000, debug=True)
Thank you for any help you can provide!
