SaveChanges() is saving Unchanged records

Question

I don't know if I'm missing something... anyway:

You can see, for example, that the object with the property 'HomeTeam' = ' Forest Green Rovers' has the state = 'Unchanged'. Anyway all entities are 'unchanged' in my case. So, if I'm correct, the saveChanges shouldn't try to insert those in my table but that's what it's happening:

The primary key has been violated, but EF shouldn't have tried to add this record (the one with the property HomeTeam = 'Forest Green Rovers') since it's 'Unchanged', right?

Why is EF doing that?

The entity:

{
using System;
using System.Collections.Generic;

public partial class MatchInfo
{
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
    public MatchInfo()
    {
        this.Sport = "Soccer";
        this.OddsInfoes1X2 = new HashSet<OddsInfo1X2>();
        this.Odds1X2Movements = new HashSet<OddsMovement>();
        this.OddsInfoOverUnders = new HashSet<OddsInfoOverUnder>();
        this.OddsMovementOverUnders = new HashSet<OddsMovementOverUnder>();
        this.HistoryResults = new HashSet<HistoryResult>();
    }

    public string League { get; set; }
    public System.DateTime Date { get; set; }
    public string HomeTeam { get; set; }
    public string AwayTeam { get; set; }
    public string FinalScore { get; set; }
    public string Sport { get; set; }

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<OddsInfo1X2> OddsInfoes1X2 { get; set; }
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<OddsMovement> Odds1X2Movements { get; set; }
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<OddsInfoOverUnder> OddsInfoOverUnders { get; set; }
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<OddsMovementOverUnder> OddsMovementOverUnders { get; set; }
    public virtual TeamsStatFinal TeamsStatFinal { get; set; }
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<HistoryResult> HistoryResults { get; set; }
}

}

More Info:

foreach (something){
     /*iterating on a web page and where I build the object oMatchInfo */
     if (oMatchInfo != null)
     {
          oMatchInfoTemp = (from m in context.MatchInfoes where m.HomeTeam == oMatchInfo.HomeTeam && m.AwayTeam == oMatchInfo.AwayTeam && m.Date == oMatchInfo.Date select m).FirstOrDefault<MatchInfo>();
          if (oMatchInfoTemp == null)
          {
              context.MatchInfoes.Add(oMatchInfo);
          }
          else
          {                                         
              context.OddsInfoes1X2.AddRange(oMatchInfo.OddsInfoes1X2);
          }
     }

}
/* here there is the context.saveChanges() - the context is the same */

ops. I have found my error and it's really stupid :-( in a related function inside the for there was some uncommented code where I was adding entities without checking the PK constraints. The state 'Unchanged' (first image) confused me and I have kept focusing on that... Sorry :-)

Answer 1

If you want to add entities to the context that are not new entities (the PK already exists in the database) then you need to Attach the entity rather than Add it.

More details here https://msdn.microsoft.com/en-us/library/jj592676(v=vs.113).aspx

To elaborate, look through the context contents carefully. You will find an entity that has the Added state.

Answer 2

You're adding an existing entry to the database.

if (oMatchInfo != null)
{
    oMatchInfoTemp = (from m in context.MatchInfoes where m.HomeTeam == 
    oMatchInfo.HomeTeam && m.AwayTeam == oMatchInfo.AwayTeam && m.Date == 
    oMatchInfo.Date select m).FirstOrDefault<MatchInfo>();

    if (oMatchInfoTemp == null)
    {
        context.MatchInfoes.Add(oMatchInfo);
    }
    else
    {                                         
        context.OddsInfoes1X2.AddRange(oMatchInfo.OddsInfoes1X2);
    }
}

This way you're adding a model that has an ID which matches the entry in the database, therefore your database is giving the cannot insert duplicate key error.