Sample for Entity Framework 6 + Code First + Oracle 12c

Question

I have a problem with a Visual Studio solution using Entity Framework 6 + Code First + Oracle 12c. I'm not sure it is properly configured, or if I missed something simple.

I tried to look for a sample project as a start, but was not able to find - google search, stackoverflow etc.

Is there a minimalistic sample project somewhere, which tries to create the database when runs?

Update: Just to make sure, I'm not asking anyone to create a sample for me. Before I'll do it, I want to make sure there is really no existing sample (which is strange for me, but very well might be the case).

Answer 1

I managed to create a working sample. Found some (not so) documented strange behaviors resulting in run time errors along the way.

Here is the full sample source: https://drive.google.com/file/d/0By3P-kPOnpiGRnc0OG5ZTDl6eGs/view?usp=sharing&resourcekey=0-ecT1EU81wJOQWokVDr_r9w

I created the sample with Visual Studio 2013. Used nuget to pull

• EntityFramework 6.1.3
• Official Oracle ODP.NET, Managed Entity Framework Driver 12.1.021

The important parts are

• Program.cs
• Context.cs
• TestEntity.cs
• App.config

I omit

• packages.config
• AssemblyInfo.cs
• csproj, sln files I also omit namespaces.

using System.Data.Entity;

public class Program
    {
        private static void Main(string[] args)
        {
            string connStr =
                "Data Source=(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=***server***)(PORT=1521))(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=***SERVICE***)));Persist Security Info=True;User ID=***User***;Password=***password***";

            Database.SetInitializer(new DropCreateDatabaseIfModelChanges<Context>());
            //Database.SetInitializer(new DropCreateDatabaseAlways<Context>());

            Context context = new Context(connStr);

            TestEntity te = new TestEntity();
            te.Id = 1;
            te.Name = "Test1";

            context.TestEntities.Add(te);

            context.SaveChanges();
        }
    }

---

using System.Data.Entity;

public class Context : DbContext
{
    public Context(string nameOrConnectionString)
        : base(nameOrConnectionString)
    {
    }

    public virtual DbSet<TestEntity> TestEntities { get; set; }

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        modelBuilder.HasDefaultSchema("OTS_TEST_EF");

        modelBuilder.Entity<TestEntity>()
            .Property(e => e.Id)
            .HasPrecision(9, 2);

        base.OnModelCreating(modelBuilder);
    }
}

---

using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;

[Table("TestEntity")]
public class TestEntity
{
    [Column(TypeName = "number")]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public decimal Id { get; set; }

    [StringLength(100)]
    public string Name { get; set; }
}

---

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <configSections>
    <!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
    <section name="entityFramework"
      type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"
      requirePermission="false"/>
    <section name="oracle.manageddataaccess.client"
      type="OracleInternal.Common.ODPMSectionHandler, Oracle.ManagedDataAccess, Version=4.121.2.0, Culture=neutral, PublicKeyToken=89b483f429c47342"/>
  </configSections>
  <startup>
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5"/>
  </startup>
  <entityFramework>
    <!--<defaultConnectionFactory type="System.Data.Entity.Infrastructure.SqlConnectionFactory, EntityFramework"/>-->
    <providers>
      <!--<provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer"/>-->
      <provider invariantName="Oracle.ManagedDataAccess.Client"
        type="Oracle.ManagedDataAccess.EntityFramework.EFOracleProviderServices, Oracle.ManagedDataAccess.EntityFramework, Version=6.121.2.0, Culture=neutral, PublicKeyToken=89b483f429c47342"/>
    </providers>
  </entityFramework>
  <system.data>
    <DbProviderFactories>
      <remove invariant="Oracle.ManagedDataAccess.Client"/>
      <add name="ODP.NET, Managed Driver" invariant="Oracle.ManagedDataAccess.Client" description="Oracle Data Provider for .NET, Managed Driver"
        type="Oracle.ManagedDataAccess.Client.OracleClientFactory, Oracle.ManagedDataAccess, Version=4.121.2.0, Culture=neutral, PublicKeyToken=89b483f429c47342"/>
    </DbProviderFactories>
  </system.data>
  <runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <dependentAssembly>
        <publisherPolicy apply="no"/>
        <assemblyIdentity name="Oracle.ManagedDataAccess" publicKeyToken="89b483f429c47342" culture="neutral"/>
        <bindingRedirect oldVersion="4.121.0.0 - 4.65535.65535.65535" newVersion="4.121.2.0"/>
      </dependentAssembly>
    </assemblyBinding>
  </runtime>
  <!--<oracle.manageddataaccess.client>
    <version number="*">
      <dataSources>
        <dataSource alias="SampleDataSource" descriptor="(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=localhost)(PORT=1521))(CONNECT_DATA=(SERVICE_NAME=INFOTEST))) "/>
      </dataSources>
    </version>
  </oracle.manageddataaccess.client>-->
  <!--<connectionStrings>
    <add name="OracleDbContext" providerName="Oracle.ManagedDataAccess.Client"
      connectionString="Data Source=(DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))(CONNECT_DATA =(SERVER = DEDICATED)(SERVICE_NAME = INFOTEST)));Persist Security Info=True;User ID=user;Password=password"/>
  </connectionStrings>-->
</configuration>

---

The strange thing I found on the way: Adding any of the following TypeNames will result in "Sequence contains no matching element" error.

    /*[Column(TypeName = "numeric")]*/
    /*[Column(TypeName = "number(18,0)")]*/
    /*[Column(TypeName = "number(18,2)")]*/

Indicating precision with scale 0

modelBuilder.Entity<TestEntity>().Property(e => e.Id).HasPrecision(9, 0);

Will result in

Schema specified is not valid. Errors:

(7,12) : error 2019: Member Mapping specified is not valid. The type 'Edm.Decimal[Nullable=False,DefaultValue=,Precision=9,Scale=0]' of member 'Id' in type 'EF6_Oracle12c_CF.TestEntity' is not compatible with 'OracleEFProvider.number

Omitting the

modelBuilder.HasDefaultSchema("OTS_TEST_EF");

line will result in

ORA-01918: user does not exists

It is also happened that I got

ORA-00955: name is already being used by existing object

or

Model compatibility cannot be checked because the database does not contain model metadata. Model compatibility can only be checked for databases created using Code First or Code First Migrations.

I managed to overcome those by enabling the

Database.SetInitializer(new DropCreateDatabaseAlways<Context>());

line, instead of the DropCreateDatabaseIfModelChanges mode.

Answer 2

This has the a good sample if you are still interested . It is available on 11 g .

http://www.oracle.com/webfolder/technetwork/tutorials/obe/db/dotnet/CodeFirst/index.html