如何在C＃中将DataGridView的数据引用到SQL数据库中？

Question

I am new to database and C#. I am building an EPOS software and I just want to reference the data which is in DataGridView into SQL database (if I am saying it correct). Ok, here is what I am trying to do:

as shown in the photo, I have customer1 order details (3 rows) in DataGridView and this details is only for one customer1. Now when I finish with customer1, its order details is saved in database. Next, when I finish with customer2 order, its details is saved in database. Next, customer3 order details will be saved in database.... and so on.

Now for example at some point in the future I want to read back / Edit (or check) customer2 order details from database and populate it into DataGridView.

I have been thinking how to do it but I failed and I am confused. Can you please provide me with an idea or code in how to check what did Customer2 order. thank you.

Answer 1

Create a Customer Model which represent your table. Then create a method which will return a collection. I'm going to assume you've got your connection string setup and know how to read it in your code using c#. So the code could look like:

public class Customer
{
    public int Quantity { get; set; }
    public string Description { get; set; }
    public double Price { get; set; }
}

public List<Customer> GetCustomerData()
{
  var list = new List<Customer>();

  string sqlQuery = "SELECT Qty, Des, Price From MyTable Where Customer = SomeCustomer"; //Change accordingly
  string connectionString = "Your Connection String";

  using (var connection = new SqlConnection(connectionString))
  {
    using (var cmd = new SqlCommand(sqlQuery, connection))
    {
      connection.Open();

       using (var reader = cmd.ExecuteReader())
       {
         while (reader.Read())
         {
            var c = new Customer();
            c.Quantity = Convert.ToInt32(reader["Qty"]);
            c.Description = reader["Des"].ToString();
            c.Price = Convert.ToDouble(reader["Price"]);

            list.Add(c);
          }
       }
     }
   }
   return list;
}

Finnaly to display the data on the DataGrid you'll do:

MyGrid.ItemsSource = GetCustomerData(); //Change MyGrid to whatever you've named your grid

Please note: I haven't tested the above code so it might require some small changes. However it should give you a good idea.