So, you use Entity Framework Core, and you usually code your selects like the following, maybe you are getting too much data.
var products = Products
.Where(p => p.UnitsInStock > 0)
.OrderBy(p => p.ProductName)
.ToList()
Running the query above, on my table, you'll get the following output, take a look at how many columns you are getting back from your database.
In my case, I only care about the Title, PublishedData, and a small description. So to get back only these fields, we have a few options. In the first one, we'll set the fields and return them as a dynamic object, the second one, is to give the .NET a class to use.
var products = Products
.Select(p => new {p.ProductID, p.ProductName, p.UnitsInStock, p.UnitPrice})
//.Select(p => new ProductDTO {p.ProductID, p.ProductName, p.UnitsInStock, p.UnitPrice})
.Where(p => p.UnitsInStock > 0)
.OrderBy(p => p.ProductName)
.ToList()