sql_connection.py

import datetime

try:
 from PyQt4.QtSql import *
 from PyQt4.QtCore import QT_VERSION_STR
except:
 from PyQt5.QtSql import *
 from PyQt5.QtCore import QT_VERSION_STR

class SQLConnection:
 def __init__(self,path):
 self.path = path
 self.db = None

 def open_database(self):
 if self.db:
 self.close_database()

 self.db = QSqlDatabase.addDatabase("QSQLITE")
 if QT_VERSION_STR < '5':
 path = self.path
 else:
 path = self.path[0]
 self.db.setDatabaseName(path)
 ok = self.db.open()
 return ok

 def close_database(self):
 """closes the datbase that is currently open"""
 #del self.model
 #del self.query_result
 self.db.close()
 #del self.db
 QSqlDatabase.removeDatabase("conn")

 def closeEvent(self, event):
 """closes the database if a close event occurs -
 such as close window/quit application"""
 self.close_database()

 #customer queries
 def add_new_customer(self,details):
 query = QSqlQuery()
 query.prepare("""INSERT INTO customer (FirstName,LastName,Street,Town,PostCode,TelephoneNumber) VALUES
 (?,?,?,?,?,?)""")
 query.addBindValue(details['first_name'])
 query.addBindValue(details['last_name'])
 query.addBindValue(details['street'])
 query.addBindValue(details['town'])
 query.addBindValue(details['post_code'])
 query.addBindValue(details['telephone'])
 query.exec_()

 def find_existing_customers_by_number(self,values):
 model = QSqlQueryModel()
 query = QSqlQuery()
 query.prepare("""SELECT * FROM customer WHERE CustomerID = ?""")
 query.addBindValue(values[0])
 query.exec_()
 model.setQuery(query)
 return model

 def find_existing_customers_by_name(self,values):
 model = QSqlQueryModel()
 query = QSqlQuery()
 query.prepare("""SELECT * FROM customer WHERE FirstName = ? and LastName = ?""")
 query.addBindValue(values[0])
 query.addBindValue(values[1])
 query.exec_()
 model.setQuery(query)
 return model

 def find_existing_customers_by_postcode(self,values):
 model = QSqlQueryModel()
 query = QSqlQuery()
 query.prepare("""SELECT * FROM customer WHERE PostCode = ?""")
 query.addBindValue(values[1])
 query.exec_()
 model.setQuery(query)
 return model

 def current_products(self):
 model = QSqlRelationalTableModel()
 print(self.db.tables())
 model.setTable(self.db.tables()[2])
 model.setRelation(3,QSqlRelation("ProductType","ProductTypeID","Description"))
 model.select()
 return model

 def create_new_order_for_customer(self,customer_id):
 query = QSqlQuery()
 query.prepare("""INSERT INTO CustomerOrder(Date,Time,CustomerID) values (?,?,?)""")
 today = datetime.datetime.today()
 date = today.strftime("%Y-%m-%d")
 time = today.strftime("%H:%M:%S")
 query.addBindValue(date)
 query.addBindValue(time)
 query.addBindValue(customer_id)
 query.exec_()
 return date, time

 def current_order_number(self,order_details):
 query = QSqlQuery()
 query.prepare("""SELECT * FROM CustomerOrder WHERE CustomerID = ? AND Date = ? AND Time = ?""")
 query.addBindValue(order_details['customer'])
 query.addBindValue(order_details['date'])
 query.addBindValue(order_details['time'])
 query.exec_()
 query.first()
 order = query.record()
 order_id = order.value("OrderID")
 return order_id

 def add_product_to_order_with_details(self,order_details,product_id):
 order_id = self.current_order_number(order_details)
 query = QSqlQuery()
 query.prepare("""INSERT INTO OrderItem(OrderID,ProductID,Quantity) values(?,?,1)""")
 query.addBindValue(order_id)
 query.addBindValue(product_id)
 query.exec_()

 def current_order_items(self,order_details):
 order_id = self.current_order_number(order_details)
 model = QSqlRelationalTableModel()
 model.setEditStrategy(QSqlTableModel.OnFieldChange)
 model.setTable("OrderItem")
 model.setFilter("OrderID = {0}".format(order_id))
 model.setRelation(2,QSqlRelation("Product","ProductID","Name"))
 model.select()
 return model

 def current_order_total(self,order_details):
 order_id = self.current_order_number(order_details)
 query = QSqlQuery()
 query.prepare("""SELECT SUM(Product.Price * OrderItem.Quantity) AS Total
 FROM Product, OrderItem
 WHERE OrderItem.OrderID = ?
 AND OrderItem.ProductID = Product.ProductID""")
 query.addBindValue(order_id)
 query.exec_()
 query.first()
 total = query.value(0)
 return total