排序数据列.NET C#和MS SQL

using System;
using System.Collections.Generic;

class Program
{
    static void Main()
    {
        List<int> numbers = new List<int> { 5, 3, 9, 1, 4 };

        // 升序排序
        numbers.Sort();
        Console.WriteLine("升序排序:");
        foreach (int number in numbers)
        {
            Console.WriteLine(number);
        }

        // 降序排序
        numbers.Sort((x, y) => y.CompareTo(x));
        Console.WriteLine("降序排序:");
        foreach (int number in numbers)
        {
            Console.WriteLine(number);
        }
    }
}

-- 创建示例表
CREATE TABLE Employees (
    ID INT PRIMARY KEY,
    Name NVARCHAR(100),
    Salary DECIMAL(10, 2)
);

-- 插入示例数据
INSERT INTO Employees (ID, Name, Salary) VALUES (1, 'Alice', 5000);
INSERT INTO Employees (ID, Name, Salary) VALUES (2, 'Bob', 6000);
INSERT INTO Employees (ID, Name, Salary) VALUES (3, 'Charlie', 5500);

-- 升序排序
SELECT * FROM Employees ORDER BY Salary ASC;

-- 降序排序
SELECT * FROM Employees ORDER BY Salary DESC;

// 错误的比较器示例
numbers.Sort((x, y) => x - y); // 如果x和y是字符串类型，会导致异常

// 正确的比较器示例
numbers.Sort((x, y) => string.Compare(x, y));

-- 创建索引
CREATE INDEX idx_Salary ON Employees(Salary);

-- 优化查询语句
SELECT * FROM Employees WHERE Salary > 5000 ORDER BY Salary ASC;