Convert foreach to select statement

August 1, 2024

I have below code written in foreach loop, I want to convert it to linq select method.

List<BidderDataDTO> bidsData = new List<BidderDataDTO>();

if(bidderDatas.Count > 0)
{
    foreach (var bidderData in bidderDatas)
    {
        var data = new BidderDataDTO();

        data.TenderId = bidderData.TenderId;
        data.ClosingDate = _context.Tenders.Where(x => x.Id == tenderid).Select(x => x.ClosingDate).FirstOrDefault();
        data.FullName = _context.Users.Where(x => x.Userid == bidderData.CreatedUser).Select(x => x.Firstname + " " + x.Lastname).FirstOrDefault();
        data.Price = bidderData.Price;

        bidsData.Add(data);
    }
}

I tried following, but it’s not working. So any idea on this

 bidderDatas.Select(x => new BidderDataDTO()
 {
     TenderId = x.TenderId,
     ClosingDate = _context.Tenders.Where(x => x.Id == tenderid).Select(x => x.ClosingDate).FirstOrDefault(),
     CompanyName = _context.Companies.Where(x => x.Id == x.CompanyId).Select(x => x.CompanyName).FirstOrDefault(),
     FullName = _context.Users.Where(x => x.Userid == x.CreatedUser).Select(x => x.Firstname + " " + x.Lastname).FirstOrDefault(),
     Price = x.Price,
     Email = _context.Users.Where(x => x.Userid == x.CreatedUser).Select(x => x.Email).FirstOrDefault(),
 }).ToList();

>Solution :

var bidsData = bidderDatas.Select( bd => new BidderDataDTO() {
        TenderId = bd.TenderId,
            // I think you may want  "bd.TenderId" here.
        ClosingDate = _context.Tenders.FirstOrDefault(x => x.Id == tenderid)?.ClosingDate,
        CompanyName = _context.Companies.FirstOrDefault(x => x.Id == x.CompanyId)?.CompanyName,
        FullName = _context.Users.FirstOrDefault(x => x.userid == bd.CreatedUser)?.Select(x => $"{x.Firstname} {x.Lastname}")
        Price = bd.Price,
        Email = _context.Users.FirstOrDefault(x => x.Userid == x.CreatedUser)?.Email
   });

Note this creates an IEnumerable instead of a List, but that’s often better, and if you really need a List you can call .ToList() to get it.