Inserting multiple records @ once, trying to group with 1 Id

Question

I have a program where I'm inserting multiple records at once with an order. Some thing like if a customer is ordering multiple items. I'm trying to group the items with 1 Id so I can display them with 1 Customer and multiple Items.

 

 

This is the code I'm using:

http://www.c-sharpcorner.com/UploadFile/8c19e8/dynamically-adding-and-deleting-rows-in-gridview-and-saving/

 

I'm collecting the data I get from this code and putting it into my database. I have another table with customers. I'm trying to give the customers and the group of items the same Id so I can display the customers name and the items together.

 

Thanks for any suggestions.