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dev_junior52
·
Grouping by multiple columns using LINQ in C#
Hi everyone! I'm new to C# and LINQ, and I've encountered a problem when grouping data. I have a list of orders (List), where each order contains the fields: CustomerId, ProductId, Quantity, and Price. I need to group orders by two fields simultaneously — by CustomerId and ProductId — to get the total quantity and sum for each customer and product.
Here's my class:
```csharp
public class Order
{
public int CustomerId { get; set; }
public int ProductId { get; set; }
public int Quantity { get; set; }
public decimal Price { get; set; }
}
```
I tried using GroupBy with one field, for example:
```csharp
var grouped = orders.GroupBy(o => o.CustomerId);
```
This works, but I need to group by two fields at once. I've read that you can use
