Convert MS SQL to Entity Framework - sql

Question

I trying to learn MVC, but while I try search customers purchased products I can't write with Entity Framework. I can search with MS SQL query, but I can't convert to Entity Framework.My codes;
Controller:
public ActionResult Orders()
{
Customer c = db.Customers.Find(Session["UserID"]);
List<Order> userorders= db.Orders.Where(x => x.CustomerID == c.ID).ToList();
List<OrderProduct> orderproducts = db.OrderProducts.Where(x => x.OrderID = userorders.ID); //This code not work
return View();
}
Database:
I try to convert this MS SQL code to Entity Framework;
"select ID from Products where ID IN (select ProductID from OrderProduct where OrderID IN (select ID from Orders where CustomerID = 1))"
If you can convert this MS SQL code to Entity Framework thats enough for me.
Thanks for anyone help and so sorry my bad English.

Answer 1

To retrieve all OrderProducts of the customer with ID 1, try this:
var orderProducts = db.OrderProduct
.Where(p => p.Orders.Any(o => o.Customers.Any(c => c.Id == 1)))
.ToList();
To retrieve the ID only, you can do it this way:
var productIds = db.OrderProduct
.Where(p => p.Orders.Any(o => o.Customers.Any(c => c.Id == 1)))
.Select(p => p.ProductId)
.ToList();

Answer 2

thanks for help but this is only orderproduct list. I need order list. I try this code (I edited JanneP's code. Thanks so much JanneP):
List<Product> products = (from co in db.Customers
join o in db.Orders on co.ID equals o.CustomerID
join op in db.OrderProducts on o.ID equals op.OrderID
join p in db.Products on op.ProductID equals p.ID
where co.ID == c.ID
select p).ToList();
This code find one customers ordered products. And it works.
Thanks everyone for help.

Answer 3

You could create a join condition. Also, where conditions need to be presented with two equal signs, not one. This should work:
List<OrderProduct> ürünler = (from c in db.Customers
join o in db.Orders on c.ID equals o.CustomerID
join op in db.OrderProducts on o.ID equals op.OrderID
where c.ID == 1
select op).ToList();

Answer 4

Since your database has been set up properly with Foreign Keys constraints, Entity Framework will be able to use 'navigation properties'. This allows you to write your query very easily as follows.
List<Product> products = db.Products.Where(e => e.OrderProduct.Orders.CustomerID == 1).ToList();
In your original SQL you only wanted the product IDs. Here's how you would do that.
List<int> productIds = db.Products.Where(e => e.OrderProduct.Orders.CustomerID == 1).Select(e => e.ID).ToList();
For people who have a sound grip on SQL but are new to Entity Framework and Linq, a useful search term is '101 LINQ samples'.

Answer 5

Just use the Include to retrieve the product with each order.
List<Order> userorders= db.Orders.Include(a=>a.Product).Where(x => x.CustomerID == c.ID).ToList();
This will retrieve the orders and with each order the product.
You can change the Include to add more navigation properties, I am assuming you have a Product property inside the Order class, you can change the name ift was wrong