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in Technique[技术] by (71.8m points)

c# - Update existing EntityCollection in Entity Framework

I try to work with link to entity, and i want to work directly with my entity in my application.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Calandar.Business.Manager.Data;

namespace Calandar.Business.Models.Args
{
    public class SaveExpertArgs
    {
        public ExpertEntity Expert { get; set; }
        public SaveExpertArgs(ExpertEntity expert)
        {
            Expert = expert;
        }
    }
}

public ExpertEntity SaveExpert(SaveExpertArgs args)
{            
    string connString = ConfigurationManager.ConnectionStrings["CalendarContainer"].ConnectionString;

    using (CalendarContainer dbContext = new CalendarContainer(connString))
    {             
        ExpertEntity expert = (from e in dbContext.ExpertEntities
                               where e.ExpertIdentifier == args.Expert.ExpertIdentifier
                               select e).FirstOrDefault();
        if (expert == null)
        {
            args.Expert.ExpertIdentifier = Guid.NewGuid();
            dbContext.AddToExpertEntities(args.Expert);
        }
        else
        {
            dbContext.ExpertEntities.ApplyCurrentValues(args.Expert);               

            foreach (TimeSlotEntity t in args.Expert.TimeSlotEntities)
            {
                dbContext.TimeSlotEntities.ApplyCurrentValues(t);
            }
        }              

        dbContext.SaveChanges();
        return args.Expert;
    }
}

I try to save my expert entity and it's working, but i dont know how to save my EntityCollection in my expert Entity. some body can help me ?

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by (71.8m points)

Try get rid of the else:

public ExpertEntity SaveExpert(SaveExpertArgs args)
{            
    string connString = ConfigurationManager.ConnectionStrings["CalendarContainer"].ConnectionString;

    using (CalendarContainer dbContext = new CalendarContainer(connString))
    {             
        ExpertEntity expert = (from e in dbContext.ExpertEntities
                               where e.ExpertIdentifier == args.Expert.ExpertIdentifier
                               select e).FirstOrDefault();
        if (expert == null)
        {
            args.Expert.ExpertIdentifier = Guid.NewGuid();
            dbContext.AddToExpertEntities(args.Expert);
        }
        //else
        //{
            dbContext.ExpertEntities.ApplyCurrentValues(args.Expert);               

            foreach (TimeSlotEntity t in args.Expert.TimeSlotEntities)
            {
                dbContext.TimeSlotEntities.ApplyCurrentValues(t);
            }
        //}              

        dbContext.SaveChanges();
        return args.Expert;
    }
}

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