.net数据库的操作

using System;
using System.Data.SqlClient;

class Program
{
    static void Main()
    {
        string connectionString = "Server=myServerAddress;Database=myDataBase;User Id=myUsername;Password=myPassword;";
        try
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();
                Console.WriteLine("数据库连接成功！");
            }
        }
        catch (SqlException ex)
        {
            Console.WriteLine("数据库连接失败: " + ex.Message);
        }
    }
}

using System;
using System.Data.SqlClient;

class Program
{
    static void Main()
    {
        string connectionString = "Server=myServerAddress;Database=myDataBase;User Id=myUsername;Password=myPassword;";
        string sqlQuery = "SELECT * FROM Customers WHERE Country = 'USA'";

        try
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                SqlCommand command = new SqlCommand(sqlQuery, connection);
                connection.Open();
                SqlDataReader reader = command.ExecuteReader();

                while (reader.Read())
                {
                    Console.WriteLine(reader["CustomerName"]);
                }
            }
        }
        catch (SqlException ex)
        {
            Console.WriteLine("SQL 查询失败: " + ex.Message);
        }
    }
}