C#对MySQL数据库进行查询操作

using System;
using System.Collections.Generic;
using System.Text;
using MySql.Data.MySqlClient;

namespace CSharpConnectMySqlDemo1
{
    
    
    class Program
    {
    
    
        static void Main(string[] args)
        {
    
    
            string connectStr = "server=127.0.0.1;port=3306;database=mygamedb;user=root;password=root";
            MySqlConnection conn = new MySqlConnection(connectStr);  //并没有去跟数据库建立连接

            try
            {
    
    
                conn.Open();   //与MySQL数据库建立连接

                string sql = "select * from users"; //sql查询语句
                MySqlCommand cmd = new MySqlCommand(sql,conn);
                //cmd.ExecuteReader();//执行一些查询
                //cmd.ExecuteNonQuery();//插入  删除
                //cmd.ExecuteScalar();//执行一些查询，返回一些单个的值
                MySqlDataReader reader = cmd.ExecuteReader();
                //reader.Read();  //读取下一行数据。如果读取成功，返回true，如果没有下一行的话，读取失败的话，返回false
                //Console.WriteLine(reader[0].ToString() + "   " + reader[1].ToString() + "   " + reader[2].ToString());
                //reader.Read();
                //Console.WriteLine(reader[0].ToString() + "   " + reader[1].ToString() + "   " + reader[2].ToString());
                while (reader.Read())
                {
    
    
                    Console.WriteLine(reader[0].ToString()+"   "+reader[1].ToString()+"   "+reader[2].ToString());
                }
                Console.WriteLine("已经建立连接");
            }
            catch (Exception e)
            {
    
    
                Console.WriteLine(e.ToString());

            }
            finally
            {
    
    
                conn.Close();
            }

            Console.ReadKey();
        }
    }
}