ExecuteScalar函数失败必须声明标量变量“ @DeviceId”

如何解决ExecuteScalar函数失败必须声明标量变量“ @DeviceId”

我有一个接收对象列表的控制器。首先，它使用ExecuteScalar检查表中是否已存在这些对象中的任何一个。如果行已存在，则运行更新存储过程。如果没有，我们运行插入存储过程。但是，我的代码在Execute Scalar函数执行失败，该函数告诉我们“必须声明标量变量@deviceid”。我不确定错误消息是引用查询还是sql参数。

 public BaseResponse Post([FromBody]List<PendingAttachment> pendingAttachmentRequest)
    {
        PendingAttachment pendingAttachment = new PendingAttachment();
        List<sqlParameter> sqlParameters = new List<sqlParameter>() 
        {
            new sqlParameter("@Datasource",pendingAttachment.DataSource),new sqlParameter("@LastUpdated",pendingAttachment.LastUpdated),new sqlParameter("@PendingCount",pendingAttachment.PendingCount),new sqlParameter("@deviceid",pendingAttachment.deviceid),new sqlParameter("@Username",pendingAttachment.UserName),};
        try
        {           
            RequestHeaders headers = new RequestHeaders();
            var query = "SELECT count(*) FROM PendingAttachments WHERE deviceid = @deviceid AND UserName = @UserName";
            using (var onbaseConnection = MobileCompleteServer.Helpers.OnbaseAuth.Connect(headers))
            {
                var connectionString = System.Configuration.ConfigurationManager.AppSettings["ConnectionString"];

                using (sqlConnection sqlConnection = new sqlConnection(connectionString))
                {
                    sqlConnection.open();
                    using (sqlCommand comm = new sqlCommand(query,sqlConnection))
                    {
                        comm.CommandType = System.Data.CommandType.Text;
                        foreach(PendingAttachment attachment in pendingAttachmentRequest)
                        {
                            
                            comm.Parameters.AddRange(sqlParameters.ToArray());
                            comm.Parameters.Clear();
                        }
                        int rowCount = (int)comm.ExecuteScalar();   //FAILS HERE
                        if (rowCount > 0)
                        {
                            using (sqlCommand sqlComm = new sqlCommand("sp_UpdatePendingAttachments",sqlConnection))
                            {
                                sqlComm.CommandType = System.Data.CommandType.StoredProcedure;
                                foreach (PendingAttachment attachment in pendingAttachmentRequest)
                                {
                                    
                                    sqlComm.Parameters.AddRange(sqlParameters.ToArray());
                                    sqlComm.Parameters.Clear();
                                }
                                sqlComm.ExecuteNonQuery();
                            }
                        }
                        else
                        {
                            using (sqlCommand sqlCommand = new sqlCommand("sp_InsertPendingAttachments",sqlConnection))
                            {
                                sqlCommand.CommandType = System.Data.CommandType.StoredProcedure;
                                foreach(PendingAttachment attachment in pendingAttachmentRequest)
                                {
                                    
                                    sqlCommand.Parameters.AddRange(sqlParameters.ToArray());
                                    sqlCommand.Parameters.Clear();
                                }
                                sqlCommand.ExecuteNonQuery();
                            }
                        }
                    }
                }
                return new BaseResponse();
            }
        }
        catch (Exception ex)
        {
                return new BaseResponse
                {
                    Exception = ErrorCodes.Get(ex,ErrorCodes.PendingAttachmentError),ExceptionStackTrace = ex.ToString()
                };
            

        }
    }
}