Devart.Data.Oracle 9.11.980.0 An item with the same key has already been added.

[czlatea]

After upgrating to Devart.Data,Oracle 9.11.980.0 and Entity Framework 6.4 is not possible to include 2 subcollections. If only one subcollection is included the query is generated.

Working
IQueryable<City> query = new Context().Set<City>().AsQueryable();
query = query.Include("Schools");
query = query.Include("Schools.Teachers");

Working
IQueryable<City> query = new Context().Set<City>().AsQueryable();
query = query.Include("Schools");
query = query.Include("Schools.Students");

Not Working
IQueryable<City> query = new Context().Set<City>().AsQueryable();
query = query.Include("Schools");
query = query.Include("Schools.Teachers");
query = query.Include("Schools.Students");

Following exception is thrown:

System.Data.Entity.Core.EntityCommandCompilationException : An error occurred while preparing the command definition. See the inner exception for details.
----> System.ArgumentException : An item with the same key has already been added.
at System.Data.Entity.Core.EntityClient.Internal.EntityCommandDefinition..ctor(DbProviderFactory storeProviderFactory, DbCommandTree commandTree, DbInterceptionContext interceptionContext, IDbDependencyResolver resolver, BridgeDataReaderFactory bridgeDataReaderFactory, ColumnMapFactory columnMapFactory)
at System.Data.Entity.Core.EntityClient.Internal.EntityProviderServices.CreateDbCommandDefinition(DbProviderManifest providerManifest, DbCommandTree commandTree, DbInterceptionContext interceptionContext)
at System.Data.Entity.Core.Objects.Internal.ObjectQueryExecutionPlanFactory.CreateCommandDefinition(ObjectContext context, DbQueryCommandTree tree)
at System.Data.Entity.Core.Objects.Internal.ObjectQueryExecutionPlanFactory.Prepare(ObjectContext context, DbQueryCommandTree tree, Type elementType, MergeOption mergeOption, Boolean streaming, Span span, IEnumerable`1 compiledQueryParameters, AliasGenerator aliasGenerator)
at System.Data.Entity.Core.Objects.EntitySqlQueryState.GetExecutionPlan(Nullable`1 forMergeOption)
at System.Data.Entity.Core.Objects.ObjectQuery.ToTraceString()
at Temp.Tests.DevartTests.Test() in C:\dev\tfs\Dev_Gain5\Infra\Solution\Temp.Tests\DevartTests.cs:line 25
--ArgumentException
at System.ThrowHelper.ThrowArgumentException(ExceptionResource resource)
at System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add)
at System.Data.Common.CommandTrees.b.b(f A_0)
at System.Data.Common.CommandTrees.d.a(DbApplyExpression A_0)
at System.Data.Common.CommandTrees.b.b(DbExpressionBinding A_0)
at System.Data.Common.CommandTrees.d.a(DbExpressionBinding A_0)
at System.Data.Common.CommandTrees.b.a(DbProjectExpression A_0)
at System.Data.Common.CommandTrees.b.b(DbExpressionBinding A_0)
at System.Data.Common.CommandTrees.d.a(DbExpressionBinding A_0)
at System.Data.Common.CommandTrees.b.a(DbSortExpression A_0)
at System.Data.Common.CommandTrees.b.b(DbExpressionBinding A_0)
at System.Data.Common.CommandTrees.d.a(DbExpressionBinding A_0)
at System.Data.Common.CommandTrees.b.a(DbProjectExpression A_0)
at System.Data.Common.CommandTrees.b.a(DbExpression A_0)
at System.Data.Common.CommandTrees.a.a(DbQueryCommandTree A_0, bt& A_1, b& A_2)
at System.Data.Common.CommandTrees.c.a(DbQueryCommandTree A_0)
at System.Data.Common.CommandTrees.a.a(DbCommandTree A_0)
at Devart.Data.Oracle.Entity.OracleEntityProviderServices.a(al A_0, DbCommandTree A_1)
at Devart.Data.Oracle.Entity.OracleEntityProviderServices.CreateDbCommandDefinition(DbProviderManifest baseProviderManifest, DbCommandTree commandTree)
at System.Data.Entity.Core.EntityClient.Internal.EntityCommandDefinition..ctor(DbProviderFactory storeProviderFactory, DbCommandTree commandTree, DbInterceptionContext interceptionContext, IDbDependencyResolver resolver, BridgeDataReaderFactory bridgeDataReaderFactory, ColumnMapFactory columnMapFactory)


Full sample test:

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Data.Entity;
using System.Data.Entity.Infrastructure;
using System.Linq;
using Devart.Data.Oracle;
using NUnit.Framework;

namespace Temp.Tests
{
[TestFixture]
public class DevartTests
{
[Test]
public void Test()
{
IQueryable<City> query = new Context().Set<City>().AsQueryable();

query = query.Include(x=>x.Schools);
query = query.Include("Schools.Teachers");
query = query.Include("Schools.Students");


string sql = ((DbQuery<City>)query).Sql;
Assert.IsNotNull(sql);
}
}

[DbConfigurationType(typeof(Devart.Data.Oracle.Entity.OracleEntityProviderServicesConfiguration))]
public class Context : DbContext
{
public Context()
: base(new OracleConnection("[ORACLE Connection 12.2]"), false)
{
Database.SetInitializer<Context>(null);
}

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<City>();
modelBuilder.Entity<School>();
modelBuilder.Entity<Teacher>();
modelBuilder.Entity<Student>();
}
}

public class City
{
public City()
{
Schools = new List<School>();
}

[Key]
public int Id { get; set; }

public IList<School> Schools { get; set; }
}

public class School
{
public School()
{
Students = new List<Student>();
Teachers = new List<Teacher>();
}

[Key]
public int Id { get; set; }

public int CityId { get; set; }

public IList<Student> Students { get; set; }

public IList<Teacher> Teachers { get; set; }
}

public class Student
{
[Key]
public int Id { get; set; }

public int SchoolId { get; set; }
}

public class Teacher
{
[Key]
public int Id { get; set; }

public int SchoolId { get; set; }
}
}

[Shalex]

We have reproduced the issue and are investigating it. We will notify you about the result.

[Shalex]

The bug with including several subcollections in LINQ query in EF 6.4 is fixed in v9.11.1034: viewtopic.php?f=1&t=41287.