Linq to sql 两种更新

public void UpdateWorkTask_Management(ObjectModel instance)
{
//this.WorkTask_Managemnt.Attach(instance);
WorkTask_Managemnt workTask = this.WorkTask_Managemnt.Single(s => s.ID == instance.ID);
workTask.Title = instance.Title;
workTask.Content = instance.Content;
workTask.StartTime = instance.StartTime;
workTask.EndTime = instance.EndTime;
workTask.TaskStatus = instance.TaskStatus;
workTask.Priority = instance.Priority;
workTask.IsSchedule = instance.IsSchedule;
workTask.ModifyTime = instance.ModifyTime;
workTask.ScheduleID = instance.ScheduleID;
this.SubmitChanges();
}

public int UpdateSchedule_UserInfo(Schedule_Managment instance)
{
object[] parameters = new object[13];
parameters[0] = instance.ID;
parameters[1] = instance.Title;
parameters[2] = instance.Contents;
parameters[3] = instance.StartDate;
parameters[4] = instance.EndDate;
parameters[5] = instance.IsRemind;
parameters[6] = instance.RemindType;
parameters[7] = instance.RemindTime;
parameters[8] = instance.IsTask;
parameters[9] = instance.TaskID;
parameters[10] = instance.AllDay;
parameters[11] = instance.Priority;
parameters[12] = instance.ModifyTime;

StringBuilder sb = new StringBuilder();
sb.Append("UPDATE [Schedule_Managment] SET [Title]= {1},");
sb.Append("[Contents]= {2},");
sb.Append("[StartDate]= {3},");
sb.Append("[EndDate]= {4},");
sb.Append("[IsRemind]= {5},");
sb.Append("[RemindType]= {6},");
sb.Append("[RemindTime]= {7},");
sb.Append("[IsTask]= {8},");
sb.Append("[TaskID]= {9},");
sb.Append("[AllDay]= {10},");
sb.Append("[Priority]= {11},");
sb.Append("[ModifyTime]= {12} ");
sb.Append("where ID = {0} ");
return ExecuteCommand(sb.ToString(), parameters);
}

public int DeleteSchedule_UserInfo(long id)
{
return ExecuteCommand("delete from Schedule_Managment where ID = {0}", id);
}