如何使用linq通过连接按多个列分组

           join table2 in dataSource2 on table1.Column1 equals table2.Column1

           join table3 in dataSource3 on new { table1.Column2, table2.Column2 } equals new { table3.Column2, table3.Column3 }

           select new { table1, table2, table3 };

                  group data by new { data.table1.Column1, data.table2.Column2 } into groupedData

                  select new { Key = groupedData.Key, Group = groupedData };

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

public class Program
{
    public static void Main()
    {
        // 创建示例数据源
        List<Table1> dataSource1 = new List<Table1>
        {
            new Table1 { Column1 = 1, Column2 = "A" },
            new Table1 { Column1 = 2, Column2 = "B" },
            new Table1 { Column1 = 3, Column2 = "C" }
        };

        List<Table2> dataSource2 = new List<Table2>
        {
            new Table2 { Column1 = 1, Column2 = "X" },
            new Table2 { Column1 = 2, Column2 = "Y" },
            new Table2 { Column1 = 3, Column2 = "Z" }
        };

        // 使用LINQ连接和分组
        var query = from table1 in dataSource1
                    join table2 in dataSource2 on table1.Column1 equals table2.Column1
                    select new { table1, table2 };

        var groupedQuery = from data in query
                           group data by new { data.table1.Column1, data.table2.Column2 } into groupedData
                           select new { Key = groupedData.Key, Group = groupedData };

        // 输出结果
        foreach (var group in groupedQuery)
        {
            Console.WriteLine($"Group Key: {group.Key}");
            foreach (var item in group.Group)
            {
                Console.WriteLine($"Table1: {item.table1.Column1}, {item.table1.Column2}");
                Console.WriteLine($"Table2: {item.table2.Column1}, {item.table2.Column2}");
            }
            Console.WriteLine();
        }
    }
}

public class Table1
{
    public int Column1 { get; set; }
    public string Column2 { get; set; }
}

public class Table2
{
    public int Column1 { get; set; }
    public string Column2 { get; set; }
}