如何在C#中实现Table的关联查询

在C#中实现Table的关联查询可以通过使用LINQ（Language Integrated Query）来实现。LINQ是一种在C#中进行数据查询和操作的语言集成查询技术，可以方便地对数据进行筛选、排序、分组和连接操作。

下面是一个示例代码，演示如何在C#中使用LINQ进行Table的关联查询：

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

class Program
{
    static void Main()
    {
        // 创建两个示例的表格
        List<Student> students = new List<Student>
        {
            new Student { Id = 1, Name = "Alice", Age = 20, DepartmentId = 1 },
            new Student { Id = 2, Name = "Bob", Age = 22, DepartmentId = 2 },
            new Student { Id = 3, Name = "Charlie", Age = 21, DepartmentId = 1 }
        };

        List<Department> departments = new List<Department>
        {
            new Department { Id = 1, Name = "Engineering" },
            new Department { Id = 2, Name = "Marketing" }
        };

        // 使用LINQ进行关联查询
        var query = from student in students
                    join department in departments on student.DepartmentId equals department.Id
                    select new
                    {
                        student.Name,
                        student.Age,
                        DepartmentName = department.Name
                    };

        // 打印查询结果
        foreach (var result in query)
        {
            Console.WriteLine($"Name: {result.Name}, Age: {result.Age}, Department: {result.DepartmentName}");
        }
    }

    // 定义Student和Department类
    class Student
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public int Age { get; set; }
        public int DepartmentId { get; set; }
    }

    class Department
    {
        public int Id { get; set; }
        public string Name { get; set; }
    }
}

在上面的示例中，我们首先创建了两个示例的表格（students和departments），然后使用LINQ进行关联查询，将学生的姓名、年龄和所在部门的名称进行连接，最后打印查询结果。

通过这种方式，我们可以方便地在C#中实现Table的关联查询。