C#基本数据库操作

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using MySql.Data.MySqlClient;

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("lxh yyds!");
            String uri = "server=localhost;port=3308;user=root;password=123456;database=test;";
            using (MySqlConnection conn = new MySqlConnection(uri))
            {
                conn.Open();
                //查
                String sql = "select username, password from user where id = @id;";
                MySqlCommand cmd = new MySqlCommand(sql, conn);
                cmd.Parameters.Add(new MySqlParameter("id", 1));
                UserEntity user = new UserEntity();
                using (MySqlDataReader reader = cmd.ExecuteReader()) {
                    if(reader.HasRows)
                    {
                        Console.WriteLine("查询成功！");
                        while(reader.Read())
                        {
                            user.UserName = reader.GetString(0);
                            user.PassWord = reader.GetString(1);
                            Console.WriteLine(user);
                        }
                    }else
                    {
                        Console.WriteLine("查询失败！");
                    }
                }
                //增
                String createSql = "insert into user (username, password) value (@username, @password);";
                MySqlCommand createCmd = new MySqlCommand(createSql, conn);
                MySqlParameter[] createParams = { new MySqlParameter("username", "b"), new MySqlParameter("password", "bpassword")};
                createCmd.Parameters.AddRange(createParams);
                int createCount = createCmd.ExecuteNonQuery();
                if(createCount > 0)
                {
                    Console.WriteLine("创建成功！");
                } else
                {
                    Console.WriteLine("创建失败！");
                }
                //删
                String deleteSql = "delete from user where username = @username;";
                MySqlCommand deleteCmd = new MySqlCommand(deleteSql, conn);
                MySqlParameter[] deleteParams = { new MySqlParameter("username", "b")};
                deleteCmd.Parameters.AddRange(deleteParams);
                int deleteCount = deleteCmd.ExecuteNonQuery();
                if (deleteCount > 0)
                {
                    Console.WriteLine("删除成功！");
                } else
                {
                    Console.WriteLine("删除失败！");
                }
                //改
                String updateSql = "update user set password = '@newpassword' where username = @username;";
                MySqlCommand updateCmd = new MySqlCommand(updateSql, conn);
                MySqlParameter[] updateParams = { new MySqlParameter("newpassword", "999"), new MySqlParameter("username", "a")};
                updateCmd.Parameters.AddRange(updateParams);
                int updateCount = updateCmd.ExecuteNonQuery();
                if(updateCount > 0)
                {
                    Console.WriteLine("修改成功！");
                } else
                {
                    Console.WriteLine("修改失败！");
                }
            }
                
            Console.ReadKey();
        }
    }

    class UserEntity
    {
        public String UserName { get; set; }
        public String PassWord { get; set; }

        public override string ToString()
        {
            return $"UserName={UserName};Password={PassWord}";
        }
    }
}