C# EF查询到Oracle抛出“；ORA-12704：字符集不匹配“；

我试图在Oracle的EF中组合一些列，然后对这些列执行

.Contains（）

：

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();
}

public IEnumerable SearchUsers（字符串搜索）
{
search=search.ToLower（）；
return\u securityUow.Users
其中（u=>（u.FirstName.ToLower（）+“”+u.LastName.ToLower（）+“”）（“+u.NetId.ToLower（）+”）。包含（搜索））
.OrderBy（u=>u.LastName）
.ThenBy（u=>u.FirstName）
.AsEnumerable（）；
}

但是，我得到了一个例外：

{
  "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.<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)"
  }
}

{
“消息”：“发生错误。”，
“ExceptionMessage”：“执行命令定义时出错。有关详细信息，请参阅内部异常。”，
“ExceptionType”：“System.Data.Entity.Core.EntityCommandExecutionException”，
“StackTrace:”在C:\LocalRepository\OnlineSupport\SoftwareRegistration\trunk\release\SoftwareRegistration\SoftwareRegistration.WebUI\Controllers\Api\V1\UserContactController.cs中的SoftwareRegistration.Api.V1.UserContactController.Lookup（字符串搜索）中：第40行\r\n lambda\u方法（闭包、对象、对象[]）\r\n位于System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.c\u DisplayClass10.b\u 9（对象实例，对象[]方法参数）\r\n位于System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.Execute（对象实例，对象[]参数）\r\n在System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ExecuteAsync（HttpControllerContext controllerContext，IDictionary`2参数，CancellationToken CancellationToken）\r\n--从引发异常的上一个位置开始的堆栈结束跟踪---\r\n在System.Runtime.CompilerServices.TaskWaiter.ThrowForOnSuccess（任务任务）\r\n在System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification（任务任务）\r\n在System.Runtime.CompilerServices.TaskAwaiter`1.GetResult（）\r\n在System.Web.Http.Controllers.ApiControllerActionInvoker.d\u 0.MoveNext（）\r\n----从引发异常的上一个位置开始的堆栈结束跟踪----\r\n在System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess（任务任务任务）\r\n在System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification（任务任务任务任务）\r\n在System.Runtime.CompilerServices.TaskAwaiter`1.GetResult（）\r\n位于System.Web.Http.Controllers.ActionFilterResult.d\u 2.MoveNext（）\r\n---来自引发异常的上一个位置的堆栈结束跟踪----\r\n位于System.Runtime.CompilerServices.TaskWaiter.ThrowForNonSuccess（任务任务任务）\r\n位于System.Runtime.CompilerServices.TaskWaiter.HandleNonSuccessAndDebuggerNotification（任务任务任务任务任务任务）\r\n位于System.Runtime.CompilerServices.TaskAwaiter`1.GetResult（）\r\n位于System.Web.Http.Dispatcher.HttpControllerDispatcher.d_u1.MoveNext（）“，
“内部异常”：{
“消息”：“发生错误。”，
“例外消息”：“ORA-12704:字符集不匹配”，
“ExceptionType”：“Oracle.ManagedDataAccess.Client.OracleException”，
“StackTrace”：“在OracleInternal.ServiceObjects.OracleCommandImpl.VerifyExecution（OracleConnectionImpl connectionImpl，Int32&cursorId，Boolean bThrowArrayBindRelatedErrors，OracleException&ExceptionForArrayBindML，Boolean&hasMoreRowsInDB，Boolean BfirstitionDone）\r\n在OracleInternal.ServiceObjects.OracleCommandImpl.ExecuteReader（字符串commandText、OracleParameterCollection paramColl、CommandType CommandType、OracleConnectionImpl connectionImpl、OracleDataReaderImpl&rdrImpl、Int32 longFetchSize、Int64 clientInitialLOBFS、OracleDependencyImpl或LdependencyImpl、Int64[]SCnforexection、Int64[]&scnFromExecution、OracleParameterCollection和bindByPositionParamColl、Boolean和bBindParamPresent、Int64和internalInitialLOBFS、OracleException和ExceptionForArrayBindML、Boolean IsDescriptionOnly、Boolean isFromEF）\r\n位于Oracle.ManagedDataAccess.Client.OracleCommand.ExecuteReader（Boolean requery、Boolean fillRequest、CommandBehavior）\r\n位于Oracle.ManagedDataAccess.Client.OracleCommand.ExecutedDataReader（CommandBehavior行为）\r\n位于System.Data.Common.DbCommand.ExecuteReader（CommandBehavior行为）\r\n位于System.Data.Entity.Infrastructure.Interception.DbCommandDispatcher.b_uC（DbCommand t，DbCommandInterceptionContext`1 c）\r\n在System.Data.Entity.Infrastructure.InternalDispatcher`1.Dispatch[TTarget，TInterceptionContext，TResult]（TTarget目标，Func`3操作，TInterceptionContext拦截Context，Action`3正在执行，Action`3已执行）\r\n在System.Data.Entity.Infrastructure.Depatcher.DbCommandDispatcher.Reader（DbCommand命令，DBCommandInterceptOnContext InterceptOnContext）\r\n位于System.Data.Entity.Internal.InterceptableDbCommand.ExecuteDbDataReader（CommandBehavior行为）\r\n位于System.Data.Common.DbCommand.ExecuteReader（CommandBehavior行为）\r\n位于System.Data.Entity.Core.EntityClient.Internal.EntityCommandDefinition.ExecuteStorommands（EntityCommand EntityCommand，CommandBehavior）
}
}

我查询的列在Oracle中都是VARCHAR2（128）类型

我在另一个项目中也使用了完全相同的代码，它也可以工作。唯一的区别是，对于工作的项目，我使用的是

Oracle.DataAccess

，对于不工作的项目，我使用的是

Oracle.ManagedDataAccess

（我无法在此项目中使用

Oracle.DataAccess

）。因此，我认为托管驱动程序中存在错误/问题

---

我对解决方案或变通方法持开放态度。

我最终让本（）的作者更新了问题，他发布了一个使用拦截器的变通方法，我将在这里详细介绍一下

首先，我修饰了DBContext以加载配置。如果您有配置，您可以跳过此操作，只需添加到配置中：

[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<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''", "''");
    }
}

公共类NVARCHIRINTERCEPTOR:IDbCommandInter