C# Linq Improve performance of GetById Linq query

Question

I'm currently working on an ASP.NET Mvc 4.5 application and use a basic Repository Pattern. In my service implementation I'm using a GetById method, which works fine, but is unfortunately kind of slow.

I'm selecting into a ViewModel from different tables, though.

In the controller I'm calling:

var offerVm = OfferService.GetOfferById(Id);

The service class implements the method as follows:

public OfferVm GetOfferById(int id)
{
    var offer = Db.Offer
        .Where(x => x.OfferId == id)
        .Select(x => new OfferVm
        {
            OfferId = x.OfferId,
            CreatedById = x.CreatedById,
            CreatedDate = x.CreatedDate,
            Label = x.OfferData.Label,
            StatusId = x.OfferData.StatusId,
            HasPresentationDocument = x.OfferData.HasPresentationDocument,
            Actors = x.ActorPool.Actor.Select(y => new ActorVm
            {
                EmployeeId = y.EmployeeId,
                ActorTypeId = y.ActorTypeId
            }).ToList(),
            Targets = x.TargetPool.Target.Select(y => new TargetVm
            {
                IsLargeCompany = y.IsLargeCompany,
                IsSmallCompany = y.IsSmallCompany,
                IsPrivateCompany = y.IsPrivateCompany,
                IsPublicCompany = y.IsPublicCompany,
                CountryIds = y.TargetScope.Select(z => z.CountryId).ToList()
            }).ToList(),
            Swots = x.SwotPool.SWOT.Select(y => new SwotVm
            {
                SwotForId = y.SwotForId,
                SwotParts = y.SwotParts.Select(z => new SwotPartVm
                {
                    SwotTypeId = z.SwotTypeId,
                    Label = z.Label
                })
            }).ToList()
        }).FirstOrDefault();
}

Do you have some ideas/inspirations regarding Linq and on how to speed up/enhance this query ?

Thanks!!

Answer 1

If you are using Entity Framework, I highly suggest to make a Stored Procedure instead of joining it all via LINQ. There will be a big difference in terms of performance.