Unable to order by Guid column

I’m trying to order by a Guid in EF Core with a relational database and its not ordering. Is there something I’m doing wrong or could this be an issue with EF Core?

  Expected: fa1760e7-27f4-4f8b-9205-44acf2358044
  But was:  c7e76cf2-35d1-4cf8-8a67-83f41842f052

Steps to reproduce

Using NUnit I created the following test

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.Data.Sqlite;
using Microsoft.EntityFrameworkCore;
using NUnit.Framework;

namespace TestName
{
    public class BoxDbContext : DbContext
    {
        public BoxDbContext(
            DbContextOptions<BoxDbContext> options) : base(options)
        {
        }

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            modelBuilder.Entity<Box>().HasKey(x => x.Id);
            modelBuilder.Entity<Box>().Property(t => t.Id).ValueGeneratedOnAdd();
            base.OnModelCreating(modelBuilder);
        }
    }

    public class Box
    {
        public Guid Id { get; set; }
        public Guid SubId { get; set; }
    }

    [TestFixture]
    public class TestClass
    {
        private SqliteConnection SqliteConnection { get; set; }

        private DbContextOptions<BoxDbContext> Options => new DbContextOptionsBuilder<BoxDbContext>()
            .UseSqlite(SqliteConnection)
            .EnableSensitiveDataLogging()
            .Options;

        private DbContext GetDbContext()
        {
            BoxDbContext dbContext = new BoxDbContext(Options);
            dbContext.Database.EnsureCreated();
            return dbContext;
        }

        [SetUp]
        public void DbSetup()
        {
            SqliteConnectionStringBuilder sqliteConnectionStringBuilder = new SqliteConnectionStringBuilder
            {
                Mode = SqliteOpenMode.Memory,
                Cache = SqliteCacheMode.Private
            };
            SqliteConnection = new SqliteConnection(sqliteConnectionStringBuilder.ToString());
            SqliteConnection.Open();
        }

        [TearDown]
        public void DbTearDown()
        {
            SqliteConnection.Close();
        }

        [Test]
        public async Task OrderByGuid()
        {
            List<Guid> subIds = new List<Guid>
            {
                Guid.Parse("901CAB07-315F-4594-A5C6-C37725643DB8"),
                Guid.Parse("FA1760E7-27F4-4F8B-9205-44ACF2358044"),
                Guid.Parse("0C434803-0004-4894-8E29-597AA8BCF8E2"),
                Guid.Parse("C7E76CF2-35D1-4CF8-8A67-83F41842F052"),
                Guid.Parse("1D6F9038-B5B3-4559-9480-3A2651E52623"),
            };

            using (DbContext dbContext = GetDbContext())
            {
                foreach (Guid subId in subIds)
                {
                    dbContext.Set<Box>().Add(new Box {SubId = subId});
                }
                await dbContext.SaveChangesAsync();
            }

            IList<Box> boxs;
            using (DbContext approvalsDbContext = GetDbContext())
            {
                boxs = await approvalsDbContext
                    .Set<Box>()
                    .OrderByDescending(x => x.SubId)
                    .ToListAsync();
            }

            Assert.That(boxs.Count, Is.EqualTo(subIds.Count));
            Assert.That(boxs.ToArray()[0].SubId, Is.EqualTo(subIds[1]));
            Assert.That(boxs.ToArray()[1].SubId, Is.EqualTo(subIds[3]));
            Assert.That(boxs.ToArray()[2].SubId, Is.EqualTo(subIds[0]));
            Assert.That(boxs.ToArray()[3].SubId, Is.EqualTo(subIds[4]));
            Assert.That(boxs.ToArray()[4].SubId, Is.EqualTo(subIds[2]));
        }
    }
}

Further technical details

EF Core version: EF core 2.0.0 Database Provider: Microsoft.EntityFrameworkCore.Sqlite Operating system: Windows 10 IDE: Visual Studio 2017

[ajcvickers]

@chris31389 Thanks for the info. It does indeed seem that the default ordering for GUIDs on .NET is different from that of SQL Server. No need for another issue–I have added a note to #10265 which is the general issue we have for consideration of this issue.

[bricelam]

From the docs:

Note that the order of bytes in the returned byte array is different from the string representation of a Guid value. The order of the beginning four-byte group and the next two two-byte groups is reversed, whereas the order of the last two-byte group and the closing six-byte group is the same.

…and the other docs:

When two BLOB values are compared, the result is determined using memcmp().