Question

我正在用C＃开发一个Windows窗体应用程序。我有一个查询，我想从日期到日期进行选择。结果始终为0。我的DB是一个.sdf文件，在我的表中我有一个datetime字段，用于存储订单日期为DateTime.Now，我的PC日期格式为10.12.2014，任何人都可以帮助我解释为什么这个hapening ..！是否有更好的文件格式可以在本地保存。应用程序将安装在几台PC上，日期时间格式是否有问题。你的帮助非常适合..检查请提供一些代码。

internal static DataTable SearchItemsInOrders(string searchWord, string table, int minValue, int maxValue, out DataTable dtTable, DateTime dateFrom, DateTime dateTo)
{
    string commandText = "select A.ItemName, B.Site, B.OrderId, A.Qty, B.Requester, B.Receiver, B.Date ";
    commandText += "From tblOrderLine AS A Inner join tblOrder As B on A.OrderId=B.OrderId ";
    commandText += "where A.ItemName='" + searchWord + "' and B.Date >= '" + dateFrom.ToShortDateString() + "' and B.Date <='" + dateTo.ToShortDateString() + "' Order By A.OrderId DESC";

    SqlCeDataAdapter adp = new SqlCeDataAdapter();
    SqlCeConnection con = ConAndData.Con;

    dtTable = new DataTable();
    adp = new SqlCeDataAdapter(commandText, con);
    if (con.State == System.Data.ConnectionState.Closed)
    {
      con.Open();
    }
    adp.Fill(minValue, maxValue, dtTable);
    return dtTable;
}

Answer 1

尝试使用此查询

string commandText = "select A.ItemName, B.Site, B.OrderId, A.Qty, B.Requester, B.Receiver, B.Date ";
            commandText += "From tblOrderLine AS A Inner join tblOrder As B on A.OrderId=B.OrderId ";
            commandText += "where A.ItemName='" + searchWord + "' and CONVERT(NVARCHAR(10),B.Date,121) >= CONVERT(NVARCHAR(10),'" + dateFrom.ToString("yyyy-MM-dd") + "',121) and CONVERT(NVARCHAR(10),B.Date,121) <= CONVERT(NVARCHAR(10),'" + dateTo.ToString("yyyy-MM-dd") + "',121) Order By A.OrderId DESC";

希望这会有所帮助......

Answer 2

正如评论中建议的那样 - 您必须使用参数化查询。

所以，你的commandText应该是：

string commandText = "select A.ItemName, B.Site, B.OrderId, A.Qty, B.Requester, B.Receiver, B.Date ";
commandText += "From tblOrderLine AS A Inner join tblOrder As B on A.OrderId=B.OrderId ";
commandText += "where A.ItemName=@ItemName and B.Date >= @DateFrom and B.Date <=@DateTo Order By A.OrderId DESC";

以后您应该为命令添加参数和值：

adp = new SqlCeDataAdapter(commandText, con);
adp.SelectCommand.Parameters.Add("@ItemName", SqlDbType.NVarChar).Value = searchWord; 
adp.SelectCommand.Parameters.Add("@DateFrom", SqlDbType.DateTime).Value = dateFrom;
adp.SelectCommand.Parameters.Add("@DateTo", SqlDbType.DateTime).Value = dateTo;

这也可以防止由ToShortDateString（）生成的日期格式错误导致的问题。

从返回0的日期之间的表sql ce服务器中选择

2 个答案: