Generic Way to Implement EF6 Code First - c#-4.0

Question

I'm Using EF6 Code First (Generic Repository Concepts)
Example Code TO Create Record :
Generic.cs:
public T Create<T>(T t) where T : class
{
T newEntry = this.dbContext.Set<T>().Add(t);
this.SaveChanges();
return newEntry;
}
Actual Code :
var customer = new Customer{
Name = "Adams",
Amount = 1000
};
CustomerId is AutoIdentity Column It will Generate Id automatically.
Customer table having One To Many RelationShip with Products(CustomerID FK in Products Table)
Now I'm adding New CustomerID in the List of Products
var productsList = new List<Product>
{
new Product
{
ProdName = "crocin",
Date = DateTime.Parse("2003-09-01"),
Customer.CustomerId = newCustomerId //
},
new Product
{
ProdName = "crocin1",
Date = DateTime.Parse("2003-09-01"),
Customer.CustomerId = newCustomerId //
},
new Product
{
ProdName = "crocin2",
Date = DateTime.Parse("2003-09-01"),
Customer.CustomerId = newCustomerId //
}
};
Now I'm hitting database twice because First I'm getting CustomerId then I'm assigning New CustomerId to all the Selected Products.
Here is the code :
var newCustomer = Generic.Create<Customer>(customer);
Iterating the list of products and I'm assinging the newCustomerId into Products..
foreach(var product in productList)
{
product.CustomerId = newCustomerId;
Generic.Create<Product>(product);
}
Is it possible to change this code to more Generic way of implementing soemthing like this..
Create(T parentTable, List<T> childTableList)
{
// First Inserting ParentTable
db.SaveChanges();
//Fetching ID
// Inserting Into ChildTables..
db.SaveChanges();
}
Please suggest me to extend this code...

Answer 1

The problem is that you're missing the Customer -> Products association. Try to add a reference to Products from your Customer class:
public class Customer
{
public Customer()
{
this.Products = new List<Product>();
}
// your key
public int CustomerId { get; set; }
public string Name { get; set; }
public int Amount { get; set; }
// ... rest of your data
// the new association
public virtual ICollection<Product> Products { get; set; }
}
Now you can add them both in one call:
var productsList = new List<Product>
{
new Product
{
ProdName = "crocin",
Date = DateTime.Parse("2003-09-01"),
Customer.CustomerId = newCustomerId //
},
new Product
{
ProdName = "crocin1",
Date = DateTime.Parse("2003-09-01"),
Customer.CustomerId = newCustomerId //
},
new Product
{
ProdName = "crocin2",
Date = DateTime.Parse("2003-09-01"),
Customer.CustomerId = newCustomerId //
}
};
var newCustomer = new Customer();
foreach (var product in productsList)
newCustomer.Products.Add(product);
Then adding them to the context:
var newCustomer = Generic.Create<Customer>(newCustomer);