C#从数据库mysql读取数据

            using
             System;

            using
             System.Collections.Generic;

            using
             System.ComponentModel;

            using
             System.Data;

            using
             System.Drawing;

            using
             System.Linq;

            using
             System.Text;

            using
             System.Threading.Tasks;

            using
             System.Windows.Forms;

            using
             MySql.Data.MySqlClient;

            namespace
             电子商务
{
    
            public
            partial
            class
             Form1 : Form
    {
        
            public
             Form1()
        {
            InitializeComponent();
        }
        
            private
            void Form1_Load(object sender, EventArgs e)
        {
        }
        privatevoid button1_Click(object sender, EventArgs e)
        {
            string str = "Host=localhost;User ID=root;Password=;Port = 3306;DataBase=animals;Charset=utf8;";
            MySqlConnection conn = new MySqlConnection(str);
            conn.Open();//
////拿到数据库并打开连接//string sql = "select *from student";
                        //MySqlCommand cmd = new MySqlCommand(sql, conn);
                        //MySqlDataAdapter mda = new MySqlDataAdapter(cmd);
                        //DataSet ds = new DataSet();
                        //mda.Fill(ds);
                        //dataGridView1.DataSource = ds.Tables[0];////MySqlDataReader dr = cmd.ExecuteReader();//conn.Close();/*1.访问数据库的五大步骤
              2.拿到要发送的sql语句
              3.执行 sql 语句
              4.拿到执行后的聚过
              5.关闭连接 切记关闭连接
            */////1 拿到数据库的连接 并打开连接//string url = "User ID=root;Password=;Host=localhost;Port=3306;Database=xx;charset=xx;";
            //MySqlConnection con = new MySqlConnection(url);
            //con.Open();////2.要拿到要发送的sql语句//string sql = "select id from student where name=‘kobe‘";
            //MySqlCommand com = new MySqlCommand(sql, con);//// 3 执行 sql 语句//MySqlDataReader reader = com.ExecuteReader();
            //reader.Read();// Read() 每次调用 都会从结果集中返回一行数据
            //reader.GetInt32(0);/*1.访问数据库的五大步骤
              2.拿到要发送的sql语句
              3.执行 sql 语句
              4.拿到执行后的聚过
              5.关闭连接 切记关闭连接
            *///1 拿到数据库的连接 并打开连接string url = "User ID=root;Password=;Host=localhost;Port=3306;Database=students;";
            MySqlConnection con = new MySqlConnection(url);
            con.Open();
            //2.要拿到要发送的sql语句string sql = "select *from student where name=‘kobe‘";
            MySqlCommand com = new MySqlCommand(sql, con);
            // 3 执行 sql 语句
            MySqlDataReader reader = com.ExecuteReader();
            reader.Read();// Read() 每次调用 都会从结果集中返回一行数据
            //reader.GetInt32(0);
            Console.WriteLine(reader.GetInt32(0));
            con.Close();
            ////对数据库进行  增  删  改  查
            ////1 拿到数据库的连接 并打开连接//string url = "User ID=root;Password=root;Host=localhost;Port=3306;Database=students;";
            //MySqlConnection con = new MySqlConnection(url);
            //con.Open();
            //string sql = "insert into student values(11,‘hahahaha‘,‘man‘,6)";//添加信息
            //MySqlCommand cmd = new MySqlCommand(sql, con);
            //int result = cmd.ExecuteNonQuery();
            //Console.WriteLine("数据库打开结果："+result);
            //con.Close();
            //FindStudent("kobe");        }
        publicstaticbool FindStudent(string name)
        {
            bool b = false;
            string url = "User ID=root;Password=root;Host=localhost;Port=3306;Database=students;";
            MySqlConnection con = new MySqlConnection(url);
            con.Open();
            string sql = "select *from studnet where name=‘{0}‘ ";
            sql = string.Format(sql, name);
            // Console.WriteLine(sql);
            MySqlCommand cmd = new MySqlCommand(sql, con);
            MySqlDataReader reader = cmd.ExecuteReader();
            b = reader.Read();
            return b;
        }
    }
}