Added Python backend solutions

solutions/backend/orders_dao.py

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+from datetime import datetime
+from sql_connection import get_sql_connection
+
+
+def get_order_details(connection, order_id):
+    cursor = connection.cursor()
+    query = ("select orders.customer_name as customer, products.name as product, quantity, total_price "
+             "from order_details "
+             "inner join orders on order_details.order_id = orders.order_id "
+             "inner join products on order_details.product_id = products.product_id "
+             "where order_details.order_id = " + str(order_id))
+
+    cursor.execute(query)
+
+    response = []
+
+    for (customer, product, quantity, total_price) in cursor:
+        response.append({
+            'customer': customer,
+            'product': product,
+            'quantity': quantity,
+            'total_price': total_price
+        }
+
+        )
+    return response
+
+
+if __name__ == '__main__':
+    connection = get_sql_connection()
+    print(get_order_details(connection, 27))

solutions/backend/products_dao.py

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+from sql_connection import get_sql_connection
+
+
+def edit_product(connection, product):
+    cursor = connection.cursor()
+    query = ("UPDATE products "
+             "set name=%s, uom_id=%s, price_per_unit=%s"
+             " WHERE product_id=%s;")
+    data = (product['name'], product['uom_id'], product['price_per_unit'], product['product_id'])
+
+    cursor.execute(query, data)
+    connection.commit()
+
+    return product['product_id']
+
+
+if __name__ == '__main__':
+    connection = get_sql_connection()
+
+    print(edit_product(connection, {
+        'product_id': 1,
+        'name': 'potatoes',
+        'uom_id': 1,
+        'price_per_unit': 10
+    }))

solutions/backend/server.py

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+from flask import Flask, request, jsonify
+from sql_connection import get_sql_connection
+import mysql.connector
+import json
+
+import products_dao
+import orders_dao
+import uom_dao
+
+app = Flask(__name__)
+
+connection = get_sql_connection()
+
+
+# Passes ID and Edits details of a product
+@app.route('/editProduct', methods=['POST', 'GET'])
+def edit_product():
+    request_payload = json.loads(request.form['data'])
+    product_id = products_dao.edit_product(connection, request_payload)
+    response = jsonify({
+        'product_id': product_id
+    })
+    response.headers.add('Access-Control-Allow-Origin', '*')
+    return response
+
+
+# Inserts new UOM
+@app.route('/insertUOM', methods=['GET', 'POST'])
+def insert_uom():
+    request_payload = json.loads(request.form['data'])
+    uom_id = uom_dao.insert_new_uom(connection,request_payload)
+    response = jsonify({
+        'uom_id': uom_id
+    })
+    response.headers.add('Access-Control-Allow-Origin', '*')
+    return response
+
+
+# Order details (customer_name, product, quantity, total_price)
+# of a particular order is fetched from the Database
+@app.route('/getOrderDetails', methods=['GET'])
+def get_order_details():
+    response = orders_dao.get_order_details(connection, request.form['order_id'])
+    response = jsonify(response)
+    response.headers.add('Access-Control-Allow-Origin', '*')
+    return response
+
+if __name__ == "__main__":
+    print("Starting Python Flask Server For Grocery Store Management System")
+    app.run(port=5000)

solutions/backend/sql_connection.py

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+import datetime
+import mysql.connector
+
+__cnx = None
+
+
+def get_sql_connection():
+    print("Opening mysql connection")
+    global __cnx
+
+    if __cnx is None:
+        __cnx = mysql.connector.connect(user='root', password='root', database='grocery_store')
+
+    return __cnx

solutions/backend/uom_dao.py

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+from sql_connection import get_sql_connection
+connection = get_sql_connection()
+
+
+def insert_new_uom(connection, uom):
+    cursor = connection.cursor()
+    query = f"INSERT INTO uom (uom_name) VALUES ('{uom['name']}');"
+    cursor.execute(query)
+    connection.commit()
+    return cursor.lastrowid
+
+
+if __name__ == '__main__':
+
+    print(insert_new_uom(connection, {
+        'name': 'cubic meter'
+    }))