实体框架查询

Question

I' ve got tables: Customer, Order, Product

Customer has gor a lot of orders, each order has got a lot wof products.

How can I write query to get all products from Customer ? I need to use it as a datasource, thanks for help bye

Answer 1

This should work:

var result = customer
                .SelectMany(x=>x.Orders)
                .Select(x=>x.Products)

Also you can add .Distinct() to retrieve only different products

Another way is to go from Products:

var result = dbContext.Products
                .Where(x=>x.Orders.Any(o=>o.Customer.Id == customer.Id))

Hard to read and hard to understand, but still works)

Answer 2

var products = from customer in customers
               from order in customer.Orders
               from product in order.Products
               select product;

Just use LINQ SelectMany.