EF Core GroupBy: How to Group Data by a Single Column and Select Multiple Columns

Example:

var ordersByCustomer = dbContext.Orders
    .GroupBy(o => o.CustomerId)
    .Select(g => new { 
        CustomerId = g.Key, 
        TotalAmount = g.Sum(o => o.Amount),
        AverageAmount = g.Average(o => o.Amount),
        MaxAmount = g.Max(o => o.Amount),
        MinAmount = g.Min(o => o.Amount)
    })
    .ToList();

In this example, we're using the GroupBy method to group orders by the CustomerId property. We're then using the Select method to project the grouped data into a new anonymous type that contains the CustomerId, the total amount of orders for each customer (TotalAmount), the average amount of orders for each customer (AverageAmount), the maximum amount of orders for each customer (MaxAmount), and the minimum amount of orders for each customer (MinAmount).

The ToList method is used to execute the query and return the results as a list.