.ToLinq2Db() after .AsNoTracking() produce same query, but incorrect results

[Kirill-Maurin]

Steps:

1. Use code like Details.Include(d => d.Master).AsNoTracking().ToLinq2Db().ToArray()
2. Use code like Details.Include(d => d.Master).ToLinq2Db().AsNoTracking().ToArray()

Expected result: resul of 1 == result of 2

Actual result: result of 1 duplicates same master records in memory for all details

Sample: https://github.com/Kirill-Maurin/linq2db.Sample/blob/a8c2561e379163915a4925e5a2aa91228170548f/linq2db.Sample.Tests/IdTests.cs#L140

[sdanyliv]

Any version details? And maybe you can post SQL?

[Kirill-Maurin]

Versions:

     <PackageReference Include="linq2db.EntityFrameworkCore" Version="3.6.0" />
     <PackageReference Include="Microsoft.EntityFrameworkCore" Version="3.1.7" />
     <PackageReference Include="Npgsql.EntityFrameworkCore.PostgreSQL" Version="3.1.4" />

SQL 1:

info: LinqToDB[49]
      BeforeExecute
      --  PostgreSQL.9.5 PostgreSQL

      SELECT
        t1.id,
        t1.master_id,
        t1.name,
        "a_Master".id,
        "a_Master".name
      FROM
        details t1
                INNER JOIN entitites "a_Master" ON t1.master_id = "a_Master".id

SQL 2:

info: LinqToDB[49]
      BeforeExecute
      --  PostgreSQL.9.5 PostgreSQL

      SELECT
        t1.id,
        t1.master_id,
        t1.name,
        "a_Master".id,
        "a_Master".name
      FROM
        details t1
                INNER JOIN entitites "a_Master" ON t1.master_id = "a_Master".id

[sdanyliv]

@Kirill-Maurin, linq2db does not have ChangeTracker and Identity Management. So it is expected behavior. When you enable Track changes, we use EF Core's Change Tracker, which knows about loaded entities.

[MaceWindu]

This is expected behavior. As[No]Tracking is EF.Core method, which checks that it is applied to efcore's IQueryable and if not - it does nothing. Meaning it does nothing when called after ToLinq2Db call