EFクエリ「ORA-12704：文字セットの不一致」

Question

私は、このような列の上に.Contains()を行うオラクルからEFでのいくつかの列を結合しようとしています：

public IEnumerable<User> SearchUsers(string search) 
{ 
    search = search.ToLower(); 

    return _securityUow.Users 
      .Where(u => (u.FirstName.ToLower() + " " + u.LastName.ToLower() + " (" + u.NetId.ToLower() + ")").Contains(search)) 
      .OrderBy(u => u.LastName) 
      .ThenBy(u => u.FirstName) 
      .AsEnumerable(); 
} 

しかし、私は

{ 
    "Message": "An error has occurred.", 
    "ExceptionMessage": "An error occurred while executing the command definition. See the inner exception for details.", 
    "ExceptionType": "System.Data.Entity.Core.EntityCommandExecutionException", 
    "StackTrace": " at SoftwareRegistration.WebUI.Controllers.Api.V1.UserContactController.Lookup(String search) in C:\LocalRepository\OnlineSupport\SoftwareRegistration\trunk\release\SoftwareRegistration\SoftwareRegistration.WebUI\Controllers\Api\V1\UserContactController.cs:line 40\r\n at lambda_method(Closure , Object , Object[])\r\n at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.<>c__DisplayClass10.<GetExecutor>b__9(Object instance, Object[] methodParameters)\r\n at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.Execute(Object instance, Object[] arguments)\r\n at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ExecuteAsync(HttpControllerContext controllerContext, IDictionary`2 arguments, CancellationToken cancellationToken)\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()\r\n at System.Web.Http.Controllers.ApiControllerActionInvoker.<InvokeActionAsyncCore>d__0.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()\r\n at System.Web.Http.Controllers.ActionFilterResult.<ExecuteAsync>d__2.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()\r\n at System.Web.Http.Dispatcher.HttpControllerDispatcher.<SendAsync>d__1.MoveNext()", 
    "InnerException": { 
    "Message": "An error has occurred.", 
    "ExceptionMessage": "ORA-12704: character set mismatch", 
    "ExceptionType": "Oracle.ManagedDataAccess.Client.OracleException", 
    "StackTrace": " at OracleInternal.ServiceObjects.OracleCommandImpl.VerifyExecution(OracleConnectionImpl connectionImpl, Int32& cursorId, Boolean bThrowArrayBindRelatedErrors, OracleException& exceptionForArrayBindDML, Boolean& hasMoreRowsInDB, Boolean bFirstIterationDone)\r\n at OracleInternal.ServiceObjects.OracleCommandImpl.ExecuteReader(String commandText, OracleParameterCollection paramColl, CommandType commandType, OracleConnectionImpl connectionImpl, OracleDataReaderImpl& rdrImpl, Int32 longFetchSize, Int64 clientInitialLOBFS, OracleDependencyImpl orclDependencyImpl, Int64[] scnForExecution, Int64[]& scnFromExecution, OracleParameterCollection& bindByPositionParamColl, Boolean& bBindParamPresent, Int64& internalInitialLOBFS, OracleException& exceptionForArrayBindDML, Boolean isDescribeOnly, Boolean isFromEF)\r\n at Oracle.ManagedDataAccess.Client.OracleCommand.ExecuteReader(Boolean requery, Boolean fillRequest, CommandBehavior behavior)\r\n at Oracle.ManagedDataAccess.Client.OracleCommand.ExecuteDbDataReader(CommandBehavior behavior)\r\n at System.Data.Common.DbCommand.ExecuteReader(CommandBehavior behavior)\r\n at System.Data.Entity.Infrastructure.Interception.DbCommandDispatcher.<Reader>b__c(DbCommand t, DbCommandInterceptionContext`1 c)\r\n at System.Data.Entity.Infrastructure.Interception.InternalDispatcher`1.Dispatch[TTarget,TInterceptionContext,TResult](TTarget target, Func`3 operation, TInterceptionContext interceptionContext, Action`3 executing, Action`3 executed)\r\n at System.Data.Entity.Infrastructure.Interception.DbCommandDispatcher.Reader(DbCommand command, DbCommandInterceptionContext interceptionContext)\r\n at System.Data.Entity.Internal.InterceptableDbCommand.ExecuteDbDataReader(CommandBehavior behavior)\r\n at System.Data.Common.DbCommand.ExecuteReader(CommandBehavior behavior)\r\n at System.Data.Entity.Core.EntityClient.Internal.EntityCommandDefinition.ExecuteStoreCommands(EntityCommand entityCommand, CommandBehavior behavior)" 
    } 
} 

私が照会している列は、すべてOracleのVARCHAR2（128）型です。

他のプロジェクトでもまったく同じコードを使用していますが、動作します。唯一の違いは、私がOracle.DataAccessを使っていて、うまく動かないプロジェクトのために、私はOracle.ManagedDataAccess（このプロジェクトにはOracle.DataAccessを使用できません）を使用しているということです。だから私は管理されたドライバにバグ/問題があると信じています。

解決策または回避策があります。

Answer 1

私は質問を更新するには、このの著者（ODP.Net Managed Driver - ORA-12704: character set mismatch in generated code）を取得することになった、彼はインターセプタを使用して回避策を掲示し、私はここでもう少し詳細に行くよ...

まず、私は私のDBContextを飾っ構成をロードする。あなたはこれをスキップしてちょうど持っていれば、あなたの構成に追加することができます。

[DbConfigurationType(typeof(MyDbConfiguration))] 
public partial class MyContext : DbContext 

は、Configクラスを作成します。

public class MyDbConfiguration : DbConfiguration 
{ 
    public MyDbConfiguration() 
    { 
     this.AddInterceptor(new NVarcharInterceptor()); //add this line to existing config. 
    } 
} 

次に、インターセプタを作成します。

public class NVarcharInterceptor : IDbCommandInterceptor 
{ 
    public void NonQueryExecuted(DbCommand command, DbCommandInterceptionContext<int> interceptionContext) 
    { 
     if (command != null && !string.IsNullOrWhiteSpace(command.CommandText)) 
      command.CommandText = command.CommandText.Replace("N''", "''"); 
    } 

    public void NonQueryExecuting(DbCommand command, DbCommandInterceptionContext<int> interceptionContext) 
    { 
     if (command != null && !string.IsNullOrWhiteSpace(command.CommandText)) 
      command.CommandText = command.CommandText.Replace("N''", "''"); 
    } 

    public void ReaderExecuted(DbCommand command, DbCommandInterceptionContext<DbDataReader> interceptionContext) 
    { 
     if (command != null && !string.IsNullOrWhiteSpace(command.CommandText)) 
      command.CommandText = command.CommandText.Replace("N''", "''"); 
    } 

    public void ReaderExecuting(DbCommand command, DbCommandInterceptionContext<DbDataReader> interceptionContext) 
    { 
     if (command != null && !string.IsNullOrWhiteSpace(command.CommandText)) 
      command.CommandText = command.CommandText.Replace("N''", "''"); 
    } 

    public void ScalarExecuted(DbCommand command, DbCommandInterceptionContext<object> interceptionContext) 
    { 
     if (command != null && !string.IsNullOrWhiteSpace(command.CommandText)) 
      command.CommandText = command.CommandText.Replace("N''", "''"); 
    } 

    public void ScalarExecuting(DbCommand command, DbCommandInterceptionContext<object> interceptionContext) 
    { 
     if (command != null && !string.IsNullOrWhiteSpace(command.CommandText)) 
      command.CommandText = command.CommandText.Replace("N''", "''"); 
    } 
}