static void Main(string[] args) { var customer = new List<Customer>(); using (var connection = new SqlConnection(@"Data Source=(localdb)\MSSQLLocalDB;Initial Catalog=Northwind;Integrated Security=True;Connect Timeout=30;Encrypt=False;TrustServerCertificate=False;ApplicationIntent=ReadWrite;MultiSubnetFailover=False")) { connection.Open(); Console.WriteLine(connection.State); //READ+ using (var command = new SqlCommand("select * from customers", connection)) { SqlDataReader sqlReader = command.ExecuteReader(); while (sqlReader.Read()) { //create variables for customer var customerID = sqlReader["CustomerID"].ToString(); var contactName = sqlReader["ContactName"].ToString(); var companyName = sqlReader["CompanyName"].ToString(); var city = sqlReader["City"].ToString(); var contactTitle = sqlReader["ContactTitle"].ToString(); //new customer object var customer = new Customer { CustoemrID = customerID, ContactName = contactName, CompanyName = companyName, City = city, ContactTitle = contactTitle }; customers.Add(customer); } foreach (var c in customers) { Console.WriteLine(c.GetFullName()); } //Comment out the above //Create and Insert var newCustomer = new Customer { CustomerID = "MANDA", ContactName = "Nish Mandal", City = "Birmingham", CompanyName = "Sparta Global" }; string sqlString = $"INSERT INTO CUSTOMERS(CustomerID, ContactName, City) VALUES ('{newCustomer.CustomerID}','{newCustomer.ContactName}','{newCustomer.City}',{newCustomer.CompanyName}')"; using (var command2 = new SqlCommand(sqlString,connection)) { int affected = command2.ExecuteNonQuery(); } //Comment out above //UPDATE var selectedCustomer = new Customer { CustomerID = "MANDA", ContactName = "Nish Mandal", City = "Birmingham", CompanyName = "Sparta Global" }; string sqlUpdateString = $"UPDATE CUSTOMER SET CITY = 'Berlin' WHERE CustomerID = '{selectedCustomer.CustomerID}"; using (var command3=new SqlCommand(sqlUpdateString,connection)) { int affected = command3.executenonquery(); } //Comment out above //DELETE var customerForDeletion = new Customer { CustomerID = "MANDA", ContactName = "Nish Mandal", City = "Birmingham", CompanyName = "Sparta Global" }; string sqlDeleteString = $"DELETE FROM CUSTOMERS WHERE CustomerID = '{customerForDeletion.CustomerID}'"); using (var command4 = new SqlConnect(sqlDeleteString,connection)) { int affected = command4.ExecuteNonQuery(); } //readded himself but switches City and companyName around //Using stored procedures(recreate customer before carrying on)^ //Update programme procedure using (var updateCustomerCommand = new SqlCommand("UodateCustomer", connection)) { updateCustomerCommand.CommandType = CommandType.StoredProcedure; //add parameters updateCustomerCommand.Parametes.AddWithValue("ID", "MANDA"); updateCustomerCommand.Parametes.AddWithValue("NewName", "Nish Kumar"); //run the update int affected = updateCustomerCommand.ExecuteNonQuery(); } } } }