在C#中實現Table的關聯查詢可以通過使用LINQ(Language Integrated Query)來實現。LINQ是一種在C#中進行數據查詢和操作的語言集成查詢技術,可以方便地對數據進行篩選、排序、分組和連接操作。
下面是一個示例代碼,演示如何在C#中使用LINQ進行Table的關聯查詢:
using System;
using System.Linq;
using System.Collections.Generic;
class Program
{
static void Main()
{
// 創建兩個示例的表格
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進行關聯查詢
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
};
// 打印查詢結果
foreach (var result in query)
{
Console.WriteLine($"Name: {result.Name}, Age: {result.Age}, Department: {result.DepartmentName}");
}
}
// 定義Student和Department類
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,我們首先創建了兩個示例的表格(students和departments),然后使用LINQ進行關聯查詢,將學生的姓名、年齡和所在部門的名稱進行連接,最后打印查詢結果。
通過這種方式,我們可以方便地在C#中實現Table的關聯查詢。