EF查询到Oracle抛出"ORA-12704:字符集不匹配"

我正在尝试将来自Oracle的EF中的几个列组合在一起,然后执行以.Contains()下列:

public IEnumerable 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();
}

但是,我得到了这个例外:

{
  "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.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.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.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.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.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)"
  }
}

我要查询的列都是Oracle中的VARCHAR2(128)类型.

我也在另一个项目中使用这个完全相同的代码,它的工作原理.唯一的区别是,对于我正在使用的项目Oracle.DataAccess和不起作用的项目,我正在使用Oracle.ManagedDataAccess(我无法Oracle.DataAccess用于此项目).所以我相信托管驱动程序中存在错误/问题.

我愿意接受解决方案或解决方法.

我最终得到了这个的作者(ODP.Net管理驱动程序 - ORA-12704:生成代码中的字符集不匹配)来更新问题,他使用拦截器发布了一个解决方法,我将在这里详细介绍一下...... .

首先,我装饰了我的DBContext以加载配置.你可以跳过这个,只要你有一个添加到你的配置:

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

创建配置类:

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

接下来,创建拦截器:

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

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

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

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

    public void ScalarExecuted(DbCommand command, DbCommandInterceptionContext