如何在 Linq 查询中调用 .Select 中的方法而不必编写两次选择？

Question

The following is my code that works. But as you can see I am having to write select twice

var lstCargoRequestVM = 
(from c in db.Cargo
 join v in db.Vehicles on c.VehicleID equals v.VehicleID
 join cmp in db.Companies on c.CompanyID equals cmp.CompanyID
 where c.Isdeleted == false && c.IsActive == true
 select new CargoRequestVM
 {
     CargoId = c.CargoID,
     CompanyName = cmp.CompanyName,
     VehicleNo = v.VehicleNo,
     Date = c.DateOfPassage,
     Type = c.Type.ToString()                                       

 })
 .AsEnumerable()
 .Select(x => new CargoRequestVM
 {
     CargoId = x.CargoId,
     CompanyName = x.CompanyName,
     VehicleNo = x.VehicleNo,
     Date = x.Date,
     Type = CargoElements.CargoTypeName(x.Type.ToString())                                              
 }).ToList();

Is it possible to do the same without having to write select twice? There could be more than a dozen properties in certain case. I don't want to make my code unnecessarily lengthy.

Answer 1

Probably that wouldn't have a translation to underlying database and thus you need to write basically twice. However you can apply the AsEnumerable() after where using method syntax like (assuming you in fact have a good relational schema defined and navigational properties set - in Linq you very rarely need join keyword):

stVM = db.Cargo
         .Include( c => c.Vehicle )
         .Include( c => c.Company )
       .Where( c => !c.Isdeleted && c.IsActive )
       .AsEnumerable()
       .Select( c => new CargoRequestVM
       {
         CargoId = c.CargoID,
         CompanyName = c.Company.CompanyName,
         VehicleNo = c.Vehicle.VehicleNo,
         Date = c.DateOfPassage,
         Type = CargoElements.CargoTypeName(c.Type.ToString())                                       
       }).ToList();