The value's length for key 'data source' exceeds it's limit of '128'

Question

I know that a very similar question has been asked here, but the answer didn\'t help me.

I am using Entity Framework 6 with the Oracle.ManagerDataAccess.Client.

Answer 1

My colleague has found an answer to this problem as follows:

Add another constructor to the context class to use an existing connection.

public GlobalAttributeContext(DbConnection existingConnection, bool contextOwnsConnection) 
       : base(existingConnection, true)
{
}

This is the complete context class

namespace OracleTestExeConfigAndConnStr
{
  [DbConfigurationType(typeof(OracleDBConfiguration))]
  public class GlobalAttributeContext : DbContext
  {
    public DbSet  GlobalAttributes { get; set; }

    static GlobalAttributeContext()
    {
      Database.SetInitializer(null);
    }

    public GlobalAttributeContext() : base("OracleDbContext")
    {
    }

    public GlobalAttributeContext(string nameOrConnectionString)
           : base(nameOrConnectionString)
    {
    }

    public GlobalAttributeContext(DbConnection existingConnection, bool contextOwnsConnection)
           : base(existingConnection, true)
    {
    }

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
      // We have to pass the schema name into the configuration. (Is there a better way?)
      modelBuilder.Configurations.Add(new GlobalAttribute_Config_Oracle("SchemaName")) ;
    }
  }
}

Create the database connection as a separate step and pass the connection into the context object.

string connStr = @"User Id=xxxxxxxxxxx;Password=xxxx;Data Source=(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=VS-ORACLE.xxxxxxxx.de)(PORT=1521))(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=orcl.xxxxxxxx.de)))";

using (var connection = new OracleConnection() { ConnectionString = connStr })
{
  connection.Open();
  using (var ctx = new GlobalAttributeContext(connection, true))
  {
    var globalAttributes = ctx.GlobalAttributes.ToList();
    foreach (GlobalAttribute ga in globalAttributes)
    {
      Console.WriteLine("Name: {0}, Value: {1}", ga.Attribute, ga.Value);
    }
  }
}

For completeness, this is the DBConfiguration class, which is specified as an attribute on the context class.

class OracleDBConfiguration : DbConfiguration
{
  public OracleDBConfiguration()
  {
    this.SetDefaultConnectionFactory ( new System.Data.Entity.Infrastructure.LocalDbConnectionFactory("v12.0") ) ;
    this.SetProviderServices ( "Oracle.ManagedDataAccess.Client", Oracle.ManagedDataAccess.EntityFramework.EFOracleProviderServices.Instance ) ;
    this.SetProviderFactory  ( "Oracle.ManagedDataAccess.Client", Oracle.ManagedDataAccess.Client.OracleClientFactory.Instance ) ;
  }
}

This method works from a DLL without requiring any values in app.config.