How to apply projections (Select) in the latest version of the framework?

[rbravo-msw]

Hi,

I’ve been using Ardalis.Specification in my project, and after updating to the latest version, I noticed that the Select() function has been removed. This prevents defining projections directly within specifications.

Previously, I used Select() inside a specification to return only the fields I actually needed, avoiding the need to load entire entities from the database. Without this function, it seems that I now have to fetch all properties of an entity, which could impact performance in large queries.

My questions are:

What is the recommended approach for handling projections in the latest version of the framework?
Is there any built-in alternative to avoid loading all entity properties when only a subset of fields is needed?
Are there any plans to reintroduce Select() or a similar feature in future versions?

Any guidance on how to address this issue would be greatly appreciated.
Thanks for your work on this project!

[fiseni]

Hi @rbravo-msw,

The projection feature is not removed. It's always been there and we don't intend to remove it.
There's a caveat though, you won't be able to place it at the end of the query. You must have an additional Query statement as follows.

class Customer
{
    public int Id { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
}

class CustomerSpec : Specification<Customer, string>
{
    public CustomerSpec(int id)
    {
        Query.Where(c => c.Id == id);

        Query.Select(c => c.FirstName);
    }
}

In version 9 we plan to improve the builders, and you'll be able to write everything in a single statement with Select at the end.

[ngoquoctoandev]

@fiseni This is great information, thank you so much, long time no update, I am eagerly waiting for version 9.0