Update an entity's property's values in the database whithin a repository query but before the query returns

I know my title sounds a little bit confusing but here's the better explanation:

I have an API made with ASP.NET CORE and .NET 5 where I use the repository pattern to perform all my DB queries.

For one of these queries I need to have some kind of calculation made and set the result of that calculation as the value of one of the entity's property in the database before it returns the entire object, but the calculation needs to happen before the query returns because I need the query to also return the new value inside the object.

In other words, here's what I had so far:

public async Task<IReadOnlyList<Place>> GetAllPlacesByCategoryWithRelatedDataAndFilters(Guid id, string city)
    {
        // I need the ratio to be calculated before I return "places"
        var places = await context.Places
            .Include(d => d.Category)
            .Where(d => d.CategoryId == id)
            .ToListAsync();

        foreach(var place in places)
        {
            // Ratio is a double
            place.Ratio = CalculateRatioByMultiplying(place.Amount1, place.Amount2);
            // Here's where I don't know how to really update the value inside of the
            // database, if I leave it like this then it will show the new value when
            // the query is performed but the value is still the default value in the
            // database

            // I've also tried this but this time nothing happens,
            // it doesn't even throw an Exception or anything and the value
            // is still the default value in the database
            var ratio = CalculateRatioByMultiplying(place.Amount1, place.Amount2);
            place.Ratio = ratio;
            await placeRepository.UpdateAsync(place);

            // Also the CalculateRatioByMultiplying is a method I've added to the
            // IPlaceRepository and so in this PlaceRepository too that just
            // multiplies arg1 with arg2 and returns a double
        }

        // Re-do the query with the new Ratio values for each of the places
        var places = await context.Places
            .Include(d => d.Category)
            .Where(d => d.CategoryId == id)
            .Where(d => d.Ratio != 0
            && d.City == city)
            .OrderByDescending(d => d.Ratio)
            .Take(10)
            .ToListAsync();

        return places;
    }

However, I'm also using the mediator pattern to query from the controllers ( I'm using clean architecture ) and some times I get confused as to should the calculation be made in the "GetAllPlacesByCategoryWithRelatedDataAndFiltersQueryHandler" ( where the query is called ) or in the repository directly.

Unfortunately I can't share the project or any sample code as it is a private project but I can answer any question you have of course.

Thanks for your help