MS Access，命名参数和列名称

我有以下查询，我在Access数据库上执行。该查询在Access中运行时会返回准确的结果。但是，当从代码运行时，我会返回数据库中的所有项目，即使那些超出我所搜索日期范围的项目也是如此。MS Access，命名参数和列名称

如果问题是因为参数名称是一样的，在表中的列名，所以我改变了参数名称@StartDate和@EndDate是@FromDate和@ToDate这解决了问题，我想知道，如果参数名称是不同的我得到正确的结果集。这关系到我，因为我在这个模式上工作的项目遍布各处。不过，我使用名为@Id的参数来更新Id（db表中的列名）的记录，并且工作正常。这是一个奇怪的边缘情况吗？任何人都可以阐明这种行为。

大量代码示例的道歉，但在这种情况下，我认为整个方法是必要的。

public override AcademicCycleTransportCollection FetchForDateRange(DateTime startDate, DateTime endDate) { 
    const String query = 
     "PARAMETERS \n" + 
     " @StartDate DATE, \n" + 
     " @EndDate DATE \n" + 
     " ; \n" + 
     "SELECT \n" + 
     "  [AcademicCycle].[Id] AS [Id], \n " + 
     "  [AcademicCycle].[Name] AS [Name], \n " + 
     "  [AcademicCycle].[AcademicCycleCategoryId] AS [AcademicCycleCategoryId], \n " + 
     "  [AcademicCycle].[ParentAcademicCycleId] AS [ParentAcademicCycleId], \n " + 
     "  [AcademicCycle].[StartDate] AS [StartDate], \n " + 
     "  [AcademicCycle].[EndDate] AS [EndDate], \n " + 
     "  [AcademicCycle].[IsPerpetual] AS [IsPerpetual], \n " + 
     "  [AcademicCycle].[IsLocked] AS [IsLocked] \n " + 
     "FROM \n" + 
     " AcademicCycle \n" + 
     "WHERE \n" + 
     " (StartDate <= @EndDate AND EndDate >= @StartDate) OR \n" + 
     " IsPerpetual <> 0"; 

    AcademicCycleTransportCollection transportCollection = new AcademicCycleTransportCollection(); 

    OleDbCommand _fetchForDateRangeCommand = null; 

    if (_fetchForDateRangeCommand == null) { 
     OleDbConnection connection = _parentDataConnection.Connection; 
     _fetchForDateRangeCommand = new OleDbCommand(query, connection); 
     _fetchForDateRangeCommand.Parameters.Add("@StartDate", OleDbType.Date); 
     _fetchForDateRangeCommand.Parameters.Add("@EndDate", OleDbType.Date); 
    } 

    _fetchForDateRangeCommand.Transaction = _parentDataConnection.Transaction; 

    _fetchForDateRangeCommand.Parameters["@StartDate"].Value = startDate; 
    _fetchForDateRangeCommand.Parameters["@EndDate"].Value = endDate; 

    using (OleDbDataReader dbReader = _fetchForDateRangeCommand.ExecuteReader()) { 
     NullableDataReader reader = new NullableDataReader(dbReader); 

     while (reader.Read()) { 
      AcademicCycleTransport transport = FillTransport(reader); 
      transportCollection.Add(transport); 
     } 
     if (!reader.IsClosed) { 
      reader.Close(); 
     } 
    } 

    return transportCollection; 
    }

来源

2011-02-01 Aran Mulholland