vs2010中运行，必须引用Mysql.data
/连接数据库/
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using MySql.Data;
using System.Data;
using MySql.Data.MySqlClient;

namespace 连接数据库
{
class Program
{
static void Main(string[] args)
{
MySqlConnection conn = null;
conn=new MySqlConnection(“Data Source=localhost;Database=php;User ID=root;Password=111111”);
conn.Open();
if (conn.State.ToString() == “Open”)
Console.WriteLine(“连接成功！”);
else
Console.WriteLine(“连接失败！”);
}
}
}

/执行增删改操作/
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using MySql.Data;
using System.Data;
using MySql.Data.MySqlClient;

namespace 连接数据库
{
class Program
{
static void Main(string[] args)
{
MySqlConnection conn = null;
conn=new MySqlConnection(“Data Source=localhost;Database=php;User ID=root;Password=111111”);
conn.Open();
if (conn.State.ToString() == “Open”)
Console.WriteLine(“连接成功！”);
else
Console.WriteLine(“连接失败！”);

        MySqlCommand com = new MySqlCommand();
        com.Connection = conn;
        com.CommandText = "insert into class values(1,'xiaoming',23),(2,'xiaoliang',5)";
        int i = com.ExecuteNonQuery();
        if (i > 0)
            Console.WriteLine("插入记录{0}条", i);
        else
            Console.WriteLine("插入不成功！");
    }
}

}

/查询操作/
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using MySql.Data;
using System.Data;
using MySql.Data.MySqlClient;

namespace 连接数据库
{
class Program
{
static void Main(string[] args)
{
MySqlConnection conn = null;
conn=new MySqlConnection(“Data Source=localhost;Database=php;User ID=root;Password=111111”);
conn.Open();
if (conn.State.ToString() == “Open”)
Console.WriteLine(“连接成功！”);
else
Console.WriteLine(“连接失败！”);

        MySqlCommand com = new MySqlCommand("select * from class", conn);
        MySqlDataReader dr = null;
        dr = com.ExecuteReader();
        while (dr.Read())
        {
            Console.WriteLine(dr["id"] + " " + dr["name"] + " " + dr["age"]);
        }

    }
}

}

/连续查询/
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using MySql.Data;
using System.Data;
using MySql.Data.MySqlClient;

namespace 连接数据库
{
class Program
{
static void Main(string[] args)
{
MySqlConnection conn = null;
conn=new MySqlConnection(“Data Source=localhost;Database=php;User ID=root;Password=111111”);
conn.Open();
if (conn.State.ToString() == “Open”)
Console.WriteLine(“连接成功！”);
else
Console.WriteLine(“连接失败！”);

        MySqlCommand com = new MySqlCommand("select * from class where id =1;select * from class where id =2", conn);
        MySqlDataReader dr = null;
        dr = com.ExecuteReader();
        while (dr.Read())
        {
            Console.WriteLine(dr["id"] + " " + dr["name"] + " " + dr["age"]);
        }
        if (dr.NextResult())
        {
            while(dr.Read())
                Console.WriteLine(dr["id"] + " " + dr["name"] + " " + dr["age"]);
        }

    }
}

}

SqlConnection conn;
    SqlDataAdapter adapter;
    private void button1_Click(object sender, EventArgs e)
    {
        conn = new SqlConnection("server=.;database=db_16;uid=sa;pwd=123456");//连接数据库
        SqlDataAdapter sda = new SqlDataAdapter("select * from tb_emp",conn);
        DataSet ds = new DataSet();
        sda.Fill(ds);
        dataGridView1.DataSource = ds.Tables[0];//绑定数据源到datagridView
        dataGridView1.RowHeadersVisible = false;//隐藏首列
        for (int i = 0; i < dataGridView1.ColumnCount;i++ )
        {
            dataGridView1.Columns[i].Width = 84;
        }
        button1.Enabled = false;
        dataGridView1.Columns[0].ReadOnly = true;
    }
    private DataTable dbconn(string strSql)//连接数据库，填充DataTable并返回       
  {
        conn.Open();
        this.adapter = new SqlDataAdapter(strSql, conn);
        DataTable dtSelect = new DataTable();
        int rnt = this.adapter.Fill(dtSelect);
        conn.Close();
        return dtSelect;
    }
    private void button2_Click(object sender, EventArgs e)
    {
        if (dbUpdate())                       //调用private Bool dbUpdate()并判断

        {
            MessageBox.Show("修改成功！");
        }
    }
    private Boolean dbUpdate()
    {
        string strSql = "select * from tb_emp";
        DataTable dtUpdate = new DataTable();
        dtUpdate = this.dbconn(strSql);//调用private DataTable dbconn(string strSql)并得到dtUpdate空表
        dtUpdate.Rows.Clear();
        DataTable dtShow = new DataTable();
        dtShow = (DataTable)this.dataGridView1.DataSource;//把修改后的datagridview数据绑定到dtShow表中
        for (int i = 0; i < dtShow.Rows.Count; i++)
        {
            dtUpdate.ImportRow(dtShow.Rows[i]);//把dtShow表中的数据复制到dtUpdate空表中

        }
        try
        {
            this.conn.Open();                            //打开数据库并更新
            SqlCommandBuilder CommandBuiler;
            CommandBuiler = new SqlCommandBuilder(this.adapter);
            this.adapter.Update(dtUpdate);
            this.conn.Close();
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message.ToString());
            return false;
        }
        dtUpdate.AcceptChanges();//更新数据库
        return true;
    }
}