添加对象列表到实体框架中创建的 DTO c#

Question

I have the following code in my c# controller,

[HttpGet("antifungal/{name}")]
public List<DrugInteractionDTO> test(string name)
{
    var DI = (from D1 in _context.DrugInteractions
              join D2 in _context.DrugInteractionReferences
              on D1.ID equals D2.DrugInteractionId into joined
              from D3 in joined.DefaultIfEmpty()
              where D1.AntifungalAgent.Name.ToLower().Contains(name.ToLower())
              select new DrugInteractionDTO
              {
                Severity = D1.Severity,
                SeverityAsString = D1.Severity.ToString(),
                ProDetailedInformation = D1.ProDetailedInformation,
                BasicDetailedInformation = D1.BasicDetailedInformation,
                Antifungal = D1.AntifungalAgent.Name,
                InteractingDrug = D1.InteractingDrug.GenericName,
                ID = D1.ID,
                Count = 2
                //DrugInteractionReferences
              }).ToList();

    return DI.OrderBy(x => x.InteractingDrug).ToList();
}

My DrugInteractionDTO model has a field List<DrugInteractionReferences> which I want to add to.

my two tables are interactions and references each interaction can have many references.

I'm used to using Java (Spring) and I can't figure out how to return the references that belong to each interaction in the DTO. The current application I am helping on is very old and has many many problems.

Is it possible to add the list of references to each interactionDTO which is being created in this code?

Answer 1

It is called Eager Loading query, detail entities should be retrieved not by join but subquery expression:

var DI = (from D1 in _context.DrugInteractions
          where D1.AntifungalAgent.Name.ToLower().Contains(name.ToLower())
          select new DrugInteractionDTO
          {
              Severity = D1.Severity,
              SeverityAsString = D1.Severity.ToString(),
              ProDetailedInformation = D1.ProDetailedInformation,
              BasicDetailedInformation = D1.BasicDetailedInformation,
              Antifungal = D1.AntifungalAgent.Name,
              InteractingDrug = D1.InteractingDrug.GenericName,
              ID = D1.ID,
              Count = 2,
              DrugInteractionReferences = _context.DrugInteractionReferences
                  .Where(D2 => D2.DrugInteractionId == D1.ID)
                  .ToList()
          }).ToList();

If you encounter performance issues, add .AsSplitQuery() before last .ToList()