EF 2.1 Value Conversion fails with custom type

[JohnyL]

I have custom type TimesRecords (which converts XML from database into objects) and entity which uses it:

public class TimesHistory
{
    [Key]
    public int DetailId { get; set; }
    public TimesRecords Records { get; set; }
}

Here's converter:

public class TimesHistoryConfiguration : IEntityTypeConfiguration<TimesHistory>
{
    public void Configure(EntityTypeBuilder<TimesHistory> builder)
    {
        builder
            .Property(p => p.Records)
            .HasConversion(
                tr => tr.ToString(),
                tr => new TimesRecords(tr));
    }
}

For full picture, here's T-SQL of table:

CREATE TABLE dbo.TimesHistory
(
	DetailId int not null,
	Records xml not null
);

So, when I run this simple code:

var history = context.TimesHistory.Where(th => th.DetailId == 1).First();
var times = history.Records;
MessageBox.Show($"Count: {times.Count()}");

I get the following error:

System.InvalidOperationException:
'The property 'Records' cannot be added to the entity type 'TimesHistory' because a navigation property with the same name already exists on entity type 'TimesHistory'.'

Further technical details

EF Core version: 2.1.0-preview1-final
Database Provider: Microsoft.EntityFrameworkCore.SqlServer
Operating system: Windows 10 x64 Home 1709 Build 16299.125
IDE: Visual Studio 2017 15.6.0 Preview 7.0

[ajcvickers]

@JohnyL Can you post the code for the TimesRecords class?

[JohnyL]

@ajcvickers Here are TimesRecords and related TimeRecord classes.

TimesRecords class

public class TimesRecords : IEnumerable<TimeRecord>
{
    private List<TimeRecord> timeRecords = null;

    public TimesRecords(string xml)
    {
        timeRecords = new List<TimeRecord>();
        if (xml != null)
        {
            foreach (var entry in XElement.Parse(xml).Elements())
            {
                timeRecords.Add(new TimeRecord(entry));
            }
        }
    }

    public IEnumerator<TimeRecord> GetEnumerator()
    {
        foreach (var timeRecord in timeRecords)
            yield return timeRecord;
    }

    public void Add(DateTime recordTime, int hours, int minutes)
    {
        int nextId = timeRecords.Count == 0 ? 1 : timeRecords.Max(r => r.Id) + 1;
        timeRecords.Add(new TimeRecord(nextId, recordTime, hours, minutes));
    }

    public override string ToString()
    {
        var xml = new XElement("records",
            from rec in timeRecords
            select new XElement("record",
                new XAttribute("id", rec.Id),
                new XAttribute("time", rec.RecordTime),
                new XAttribute("hours", rec.Hours),
                new XAttribute("minutes", rec.Minutes)));
        return xml.ToString();
    }

    IEnumerator IEnumerable.GetEnumerator()
    {
        return GetEnumerator();
    }
}

TimeRecord class

public class TimeRecord
{

    internal TimeRecord(int id, DateTime recordTime, int hours, int minutes)
    {
        Id = id;
        RecordTime = recordTime;
        Hours = hours;
        Minutes = minutes;
    }

    internal TimeRecord(XElement xml)
    {
        Id = int.Parse(xml.Attribute("id").Value);
        RecordTime = DateTime.Parse(xml.Attribute("time").Value);
        Hours = int.Parse(xml.Attribute("hours").Value);
        Minutes = int.Parse(xml.Attribute("minutes").Value);
    }
    public int Id { get; set; }
    public DateTime RecordTime { get; set; }
    public int Hours { get; set; }
    public int Minutes { get; set; }
}

[ajcvickers]

Looks like it could be the same root cause as #11074. @AndriySvyryd? @smitpatel?

[AndriySvyryd]

Sounds more like another case of #10765