How to produce the following json using flask-sqlachemy? - python-3.x

Question

I am creating a API endpoints using flask-sqlalchemy and marshmallow in python. For example I have two collections/tables one is items and other is stores. Items will have attributes like item_id, item_name, item_price and available stores_list. Store will have attributes like store_id, store_name, store_location and available items_list. I require the following JSON response when i request list of items.
[
{
item_id:1,
item_name:"Laptop",
item_price:"20",
store_list:[
{
store_id:1,
store_name:"ABC",
store_location:"USA"
},
{
store_id:2,
store_name:"BBC",
store_location:"USA"
},
{
store_id:3,
store_name:"CBC",
store_location:"USA"
}
]
},
{
item_id:2,
item_name:"Laptop",
item_price:"20",
store_list:[
{
store_id:1,
store_name:"ABC",
store_location:"USA"
},
{
store_id:2,
store_name:"BBC",
store_location:"USA"
},
{
store_id:3,
store_name:"CBC",
store_location:"USA"
}
]
}
......... and so on
]
I require the following JSON response when i request list of stores.
[
{
store_id:1,
store_name:"ABC",
store_location:"USA",
items_list:[
{
items_id:1,
items_name:"Laptop",
items_price:"65"
},
{
items_id:2,
items_name:"Keyboard",
items_price:"56"
},
{
items_id:3,
items_name:"Mouse",
items_price:"56"
}
]
},
{
store_id:2,
store_name:"BBC",
store_location:"UK",
items_list:[
{
items_id:1,
items_name:"Laptop",
items_price:"23"
},
{
items_id:2,
items_name:"BBC",
items_price:"Speaker"
},
{
items_id:3,
items_name:"Mouse",
items_price:"24"
}
]
}
......... and so on
]
So far I have tried the following
#ITEMS MODEL
from requests import Response
from flask import request, url_for
from datetime import datetime
from typing import List
from db import db
from models.store import Stores
#Bartiny Ingredients Generic Types Model
class Items(db.Model):
__tablename__ = "items"
item_id = db.Column(db.Integer, primary_key=True)
item_name = db.Column(db.String(100), nullable=False,)
item_price = db.Column(db.String(10), nullable=False,)
store_lsit = db.relationship('Stores', backref=db.backref('items'))
#classmethod
def find_by_name(cls, name: str) -> "Items":
return cls.query.filter_by(gen_type_name=name).first()
#classmethod
def find_by_id(cls, _id: int) -> "Items":
return cls.query.filter_by(id=_id).first()
#classmethod
def find_all(cls) -> List["Items"]:
return cls.query.all()
def save_to_db(self) -> None:
db.session.add(self)
db.session.commit()
def delete_from_db(self) -> None:
db.session.delete(self)
db.session.commit()
STORE MODEL
from requests import Response
from flask import request, url_for
from datetime import datetime
from typing import List
from db import db
from models.items import Items
#Bartiny Ingredients Generic Types Model
class Stores(db.Model):
__tablename__ = "stores"
store_id = db.Column(db.Integer, primary_key=True)
store_name = db.Column(db.String(100), nullable=False,)
store_locations = db.Column(db.String(10), nullable=False,)
items_list = db.relationship('Items', backref=db.backref('stores'))
#classmethod
def find_by_name(cls, name: str) -> "Stores":
return cls.query.filter_by(gen_type_name=name).first()
#classmethod
def find_by_id(cls, _id: int) -> "Stores":
return cls.query.filter_by(id=_id).first()
#classmethod
def find_all(cls) -> List["Stores"]:
return cls.query.all()
def save_to_db(self) -> None:
db.session.add(self)
db.session.commit()
def delete_from_db(self) -> None:
db.session.delete(self)
db.session.commit()
SCHEMAS
# Items Schema
from ma import ma
from marshmallow import pre_dump
from models.item import Items
class ItemsSchema(ma.ModelSchema):
class Meta:
model = Items
# Store Schema
from ma import ma
from marshmallow import pre_dump
from models.store import Stores
class StoresSchema(ma.ModelSchema):
class Meta:
model = Stores
Resources
# Store Resource
from flask_restful import Resource
from models.store import Stores
from schemas.store import StoresSchema
store_list_schema = StoreSchema(many=True)
class StoreList(Resource):
#classmethod
def get(cls):
return {"stores": store_list_schema.dump(Stores.find_all())}, 200
# Items Resource
from flask_restful import Resource
from models.item import Items
from schemas.item import ItemsSchema
item_list_schema = ItemsSchema(many=True)
class StoreList(Resource):
#classmethod
def get(cls):
return {"items": item_list_schema.dump(Items.find_all())}, 200
The following is the code for app starting
from flask import Flask, jsonify
from flask_restful import Api
from marshmallow import ValidationError
from db import db
from ma import ma
from resources.item import Item, ItemList
from resources.store import Store, StoreList
app = Flask(__name__)
app.config["SQLALCHEMY_DATABASE_URI"] = "sqlite:///data.db"
app.config["SQLALCHEMY_TRACK_MODIFICATIONS"] = False
api = Api(app)
#app.before_first_request
def create_tables():
db.create_all()
#app.errorhandler(ValidationError)
def handle_marshmallow_validation(err):
return jsonify(err.messages), 400
jwt = JWTManager(app)
api.add_resource(StoreList, "/stores")
api.add_resource(ItemList, "/items")
if __name__ == "__main__":
db.init_app(app)
ma.init_app(app)
app.run(port=5000, debug=True)

Answer 1

Looks like jsonify is your friend...
https://www.google.com/search?q=flask+sqlalchemy+to+json