如何按日期时间在datatable中搜索 [英] How to search in datatable by datetime

问题描述

Hello Everyone，

我有一个DataTable，包含三列ID，Shift Start和Shift End

ID | Shift开始| Shift End

1 | 4/12/2018 7:00:00 AM | 4/12/2018 11:00:00 PM

现在问题是我要选择此日期和时间内的所有记录。我尝试了以下代码，但没有工作。

请帮帮我。

提前致谢。



我的尝试：



//这是我要搜索的持续时间的关键时间/时间范围

Hello Everyone,
I have a DataTable that contains three columns ID, Shift Start and Shift End
ID | Shift Start | Shift End
1 | 4/12/2018 7:00:00 AM | 4/12/2018 11:00:00 PM
Now the problem is i want to select all the records within this date and time. I tried the following code but not working.
Please help me out.
Thanks in advance.

What I have tried:

// This is key time / time frame in which duration i want to search

DateTime d = Convert.ToDateTime("4/12/2018 22:53");
           string strD = d.ToString("hh:mm:ss tt");
           // Presuming the DataTable has a column named Date.
           string expression;
           expression = "[Shift Start] > #4/12/2018 " + strD + "# AND [Shift End] < #4/12/2018 " + strD + "#";
           DataRow[] foundRows;

           // Use the Select method to find all rows matching the filter.
           foundRows = dt.Select(expression);

           // Print column 0 of each returned row.
           for (int i = 0; i < foundRows.Length; i++)
           {
               MessageBox.Show(foundRows[i][1].ToString());
           }

推荐答案

您可以像这样使用 LINQ ：

You can use LINQ like this:

IEnumerable<DataRow> selectedRows = dt1.AsEnumerable()
    .Where(row => (row.Field<DateTime>("Shift Start") <= d) && (d <= row.Field<DateTime>("Shift End")));

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

这是我的完整示例，在VS2017中使用.NET 4.5.1进行了测试：

Here is my complete example, tested in VS2017 with .NET 4.5.1:

using System;
using System.Collections.Generic;
using System.Data;
using System.Diagnostics;
using System.Linq;
using System.Windows.Forms;

namespace TestForm1
{
    /// <summary>
    /// Codeproject DataTable
    /// </summary>
    public partial class Form1 : Form
    {
        DataTable dt1 = new DataTable();

        public Form1()
        {
            InitializeComponent();
            Test();
        }

        private void Test()
        {
            // Add columns
            dt1.Columns.Add("Shift Start", typeof(DateTime));
            dt1.Columns.Add("employee_id", typeof(string));
            dt1.Columns.Add("employee_name", typeof(string));
            dt1.Columns.Add("Shift End", typeof(DateTime));

            DateTime d = DateTime.Now;

            // Add test data
            dt1.Rows.Add(d.AddMinutes(-10), "1", "PRINCE", d.AddMinutes(-1));
            dt1.Rows.Add(d, "2", "KING", d.AddMinutes(2));
            dt1.Rows.Add(d.AddMinutes(1), "3", "PAUPER", d.AddMinutes(2));

            IEnumerable<DataRow> selectedRows = dt1.AsEnumerable()
                .Where(row => (row.Field<DateTime>("Shift Start") <= d) && (d <= row.Field<DateTime>("Shift End")));

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

与您的问题无关，但列中没有空格或表名 - 文件和文件夹名称相同 - 只是说： - ）

Nothing to do with your question but never have spaces in column or table names - same goes for file and folder names - just sayin :-)

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