数据表按确切的DateTime选择 [英] DataTable Select by exact DateTime

问题描述

我有一个数据表 xData ，其中的 DateTime 列具有毫秒精度，我需要提取其中的行精确匹配时间（以毫秒为单位），但语法不正确。

I have a DataTable xData which has a DateTime column with millisecond accuracy, I need to extract the rows which match an exact time with milliseconds but cannot get the syntax correct.

我尝试过

DateTime dt = timeStampList[i];
string str = dt.ToString("yyyy-MM-dd HH:mm:ss.fff");
DataRow[] result = xData.Select("TimeStamp2 = " + str);

foreach (DataRow row in result)
{
    Console.WriteLine("{0}, {1}", row[0], row[1]);
}

但

DataRow[] result = xData.Select("TimeStamp2 = " + str);

导致错误：

语法错误：'16'运算符后缺少操作数。

Syntax error: Missing operand after '16' operator.

我已经搜索过，但大多数示例仅显示如何选择日期而不是完整的 datetime （以毫秒为单位）。

I've searched but most of the examples only show how to select by date and not a full datetime with milliseconds.

推荐答案

问题在于您必须将要查找的日期/时间传递给过滤器。

The problem is that you have to pass the date/time you're looking for to your filter.

起初，我认为选择，但是根据德米特里的回答。

At first I thought that sub second precision was not supported by Select but according to Dmitry's answer it is.

另一种方法是使用对数据集的查询，它可以避免序列化日期/时间：

Another approach is to use Linq to DataSet which allows you to avoid serializing the date/time:

DateTime dt = timeStampList[i];

IEnumerable<DataRow> selectedRows = 
  xData.AsEnumerable().Where(row => (row.Field<DateTime>("TimeStamp2") == dt));

foreach (DataRow row in selectedRows)
{
  Console.WriteLine("{0}, {1}", row[0], row[1]);
}

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