Integrate flask-sqlalchemy into project - flask

Question

I am new comer of flask api. I am doing a flask restful api project which purpose is to search stores by store name that is kept in existing database online.
Now is is connect to database using psycopg2.
I would like to improve it by using flask-sqlalchemy. I have searched on the web and the solution seems to use Automap, that I learned from the tutorial. The problem I am facing now is how to integrate those codes into my existing project, like where should I put the settings like automap_base() into my existing codes. Here is my current file structure:
app.py
∟ models
∟ family_mart.py
∟ resources
∟ family_mart.py
app.py:
from flask import Flask
from flask_restful import Api
from resources.family_mart import FamilyMart
app = Flask(__name__)
app.secret_key = 'apple'
api = Api(app)
api.add_resource(FamilyMart, '/familymart/<string:name>')
if __name__ == '__main__':
app.run(port=5000, debug=True)
family_mart.py in models folder:
import psycopg2
from config import config
class FamilyMartModel:
#classmethod
def find_by_name(cls, name):
conn = None
try:
params = config()
conn = psycopg2.connect(**params)
cur = conn.cursor()
query = f"""
SELECT extract_date
, store_name
, address
FROM cnvnt_str_fm
WHERE store_name = '{name}'
"""
cur.execute(query)
rows = cur.fetchall()
cur.close()
if rows:
result = {'store':[]}
for row in rows:
append_dict = {'extract_date':row[0].strftime('%Y-%m-%d'),
'store_name':row[1],
'address':row[2]}
result['store'].append(append_dict)
return result
except (Exception, psycopg2.DatabaseError) as error:
print(error)
finally:
if conn is not None:
conn.close()
print('Database connection closed.')
family_mart.py in resources folder:
from flask_restful import Resource
from models.family_mart import FamilyMartModel
class FamilyMart(Resource):
def get(self, name):
item = FamilyMartModel.find_by_name(name)
if item:
return item
return {'message':'Store not found.'}, 404

Answer 1

After study the documentation, I restructured my project and integrate with sqlalchemy successfully. I removed model folder and added db.py to configure the existing database, here is the detail :
New file structure:
app.py
∟ resources
∟ family_mart.py
db.py
app.py:
from flask import Flask
from flask_restful import Api
from config import config
from db import db
from resources.family_mart import FamilyMart
params = config()
DB_FULL_URL = f"postgresql+psycopg2://{params['user']}:{params['password']}#{params['host']}/{params['database']}"
app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = DB_FULL_URL
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
app.secret_key = 'apple'
api = Api(app)
api.add_resource(FamilyMart, '/familymart/<string:name>')
if __name__ == '__main__':
db.init_app(app)
app.run(port=5000, debug=True)
db.py:
from flask_sqlalchemy import SQLAlchemy
from sqlalchemy import MetaData
from sqlalchemy import Table, Column, Integer, String, DateTime
db = SQLAlchemy()
metadata_obj = MetaData()
fm_table = Table('cnvnt_str_fm', metadata_obj,
Column('extract_date', String),
Column('store_name', String),
Column('address', String)
)
family_mart.py:
from flask_restful import Resource
from db import db
from db import fm_table
class FamilyMart(Resource):
def get(self, name):
results = db.session.query(fm_table).filter_by(store_name=name).\
order_by(fm_table.c.extract_date.desc()).limit(3)
output = {'store':[]}
for row in results:
extract_date = str(row[0])
store_name = row[1]
address = row[2]
output['store'].append({'extract_date':extract_date,
'store_name':store_name,
'address':address})
return output