Question

我在DataTable中有一些如下数据。现在我想从dataTable中找到重复的版本，我该怎么办？

这是数据：

Server1, Database, MySQL,  5.5
Server2, Database, MySQL,  5.1
Server3, OS,       Ubuntu, 10.04
Server1, OS,       Ubuntu, 10.04
Server2, OS,       Ubuntu, 12.04
Server3, Language, Python, 2.6.3

Answer 1

使用linq GroupBy代码如下：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using System.Data;

namespace ConsoleApplication31
{
    class Program
    {

        static void Main(string[] args)
        {
            DataTable dt = new DataTable();
            dt.Columns.Add("Server", typeof(string));
            dt.Columns.Add("Source", typeof(string));
            dt.Columns.Add("Name", typeof(string));
            dt.Columns.Add("Version", typeof(string));

            dt.Rows.Add(new object[] { "Server1", "Database", "MySQL",  "5.5"});
            dt.Rows.Add(new object[] { "Server2", "Database", "MySQL",  "5.1"});
            dt.Rows.Add(new object[] { "Server3", "OS",       "Ubuntu", "10.04"});
            dt.Rows.Add(new object[] { "Server1", "OS",       "Ubuntu", "10.04"});
            dt.Rows.Add(new object[] { "Server2", "OS",       "Ubuntu", "12.04"});
            dt.Rows.Add(new object[] { "Server2", "OS",       "Ubuntu", "12.04"});
            dt.Rows.Add(new object[] { "Server3", "Language", "Python", "2.6.3"});

            var groups = dt.AsEnumerable().GroupBy(x => x.Field<string>("Version")).ToList();

            var results = groups.Where(x => x.Count() > 1).Select(x => new { key = x.Key, count = x.Count() });

            foreach(var item in results)
            {
                Console.WriteLine("Version : '{0}' Occurances : '{1}'", item.key, item.count);
            }
            Console.ReadLine();

        }

    }
}

从datatable c＃获取重复数据

1 个答案: