C#连接mysql实例
1、实例1
using System;
using System.Configuration;
using MySql.Data.MySqlClient;
///
/// TestDatebase 的摘要说明
///
public class TestDatebase
{
public TestDatebase()
{
//
// TODO: 在此处添加构造函数逻辑
//
}
public static void Main(String[] args)
{
MySqlConnection mysql = getMySqlCon();
//查询sql
String sqlSearch = "select * from student";
//插入sql
String sqlInsert = "insert into student values (12,'张三',25,'大专')";
//修改sql
String sqlUpdate = "update student set name='李四' where id= 3";
//删除sql
String sqlDel = "delete from student where id = 12";
//打印SQL语句
Console.WriteLine(sqlDel);
//四种语句对象
//MySqlCommand mySqlCommand = getSqlCommand(sqlSearch, mysql);
//MySqlCommand mySqlCommand = getSqlCommand(sqlInsert, mysql);
//MySqlCommand mySqlCommand = getSqlCommand(sqlUpdate, mysql);
MySqlCommand mySqlCommand = getSqlCommand(sqlDel, mysql);
mysql.Open();
//getResultset(mySqlCommand);
//getInsert(mySqlCommand);
//getUpdate(mySqlCommand);
getDel(mySqlCommand);
//记得关闭
mysql.Close();
String readLine = Console.ReadLine();
}
///
/// 建立mysql数据库链接
///
///
/// 建立执行命令语句对象
///
///
///
///
/// 查询并获得结果集并遍历
///
///
public static void getResultset(MySqlCommand mySqlCommand)
{
MySqlDataReader reader = mySqlCommand.ExecuteReader();
try
{
while (reader.Read())
{
if (reader.HasRows)
{
Console.WriteLine("编号:" + reader.GetInt32(0) + "|姓名:" + reader.GetString(1) + "|年龄:" + reader.GetInt32(2) + "|学历:" + reader.GetString(3));
}
}
}
catch (Exception)
{
Console.WriteLine("查询失败了！");
}
finally
{
reader.Close();
}
}
///
/// 添加数据
///
///
public static void getInsert(MySqlCommand mySqlCommand)
{
try
{
mySqlCommand.ExecuteNonQuery();
}
catch (Exception ex)
{
String message = ex.Message;
Console.WriteLine("插入数据失败了！" + message);
}
}
///
/// 修改数据
///
///
public static void getUpdate(MySqlCommand mySqlCommand)
{
try
{
mySqlCommand.ExecuteNonQuery();
}
catch (Exception ex)
{
String message = ex.Message;
Console.WriteLine("修改数据失败了！" + message);
}
}
///
/// 删除数据
///
///
public static void getDel(MySqlCommand mySqlCommand)
{
try
{
mySqlCommand.ExecuteNonQuery();
}
catch (Exception ex)
{
String message = ex.Message;
Console.WriteLine("删除数据失败了！" + message);
}
}
}
2、实例2
先添加引用Mysql.Data.dll 组件
在头文件中添加using MySql.Data.MySqlClient
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using MySql.Data.MySqlClient;//导入用MySql的包
using System.Data;//引用DataTable
namespace TestMysql
{
public class DBHelper
{
///
/// 得到连接对象
///
///
/// 查询操作
///
///
///
/// 增删改操作
///
/// sql语句
/// 执行后的条数
public int AddDelUpdate(string sql)
{
MySqlConnection conn = null;
MySqlCommand cmd = null;
try
{
conn = base.GetConn();
conn.Open();
cmd = new MySqlCommand(sql,conn);
int i = cmd.ExecuteNonQuery();
return i;
conn.Close();
}
catch (Exception)
{
throw;
}
}
}
}
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace TestMysql
{
public partial class Form1 : Form
{
///
/// SQLHlper类的对象
///
SQLHelper helper = new SQLHelper();
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
string name = "";
string sql = string.Format("select *from stuinfo");
DataTable dt = helper.Selectinfo(sql);
for (int i = 0; i < dt.Rows.Count; i++)
{
//从数据库得到stuname 字段的值
name+=(string)dt.Rows[i]["stuname"]+"\r\n";
}
//把得到的值放到文本框中
this.textBox1.Text = name;
}
///
/// 退出按钮
///
///
///
private void btnExit_Click(object sender, EventArgs e)
{
Application.Exit();
}
///
/// 增加按钮
///
///
///
private void btnAdd_Click(object sender, EventArgs e)
{
string sql = string.Format("insert into userinfo values('{0}','{1}')",this.txtname.Text,txtpwd.Text);
int i = helper.AddDelUpdate(sql);
if (i>0)
{
MessageBox.Show("增加成功");
}
}
}
}
3.实例3
不要用OLEDB，已过时。使用第三方组件：Mysql.Data.dll，在代码页里输入using Mysql.Data.MysqlClient
#region 建立MySql数据库连接
///
/// 建立数据库连接.
///
/// 返回MySqlConnection对象
public MySqlConnection getmysqlcon()
{
string M_str_sqlcon = "server=localhost;user id=root;password=root;database=abc"; //根据自己的设置
MySqlConnection myCon = new MySqlConnection(M_str_sqlcon);
return myCon;
}
#endregion
#region 执行MySqlCommand命令
///
/// 执行MySqlCommand
///
/// SQL语句
public void getmysqlcom(string M_str_sqlstr)
{
MySqlConnection mysqlcon = this.getmysqlcon();
mysqlcon.Open();
MySqlCommand mysqlcom = new MySqlCommand(M_str_sqlstr, mysqlcon);
mysqlcom.ExecuteNonQuery();
mysqlcom.Dispose();
mysqlcon.Close();
mysqlcon.Dispose();
}
#endregion
#region 创建MySqlDataReader对象
///
/// 创建一个MySqlDataReader对象
///
/// SQL语句
/// 返回MySqlDataReader对象
public MySqlDataReader getmysqlread(string M_str_sqlstr)
{
MySqlConnection mysqlcon = this.getmysqlcon();
MySqlCommand mysqlcom = new MySqlCommand(M_str_sqlstr, mysqlcon);
mysqlcon.Open();
MySqlDataReader mysqlread = mysqlcom.ExecuteReader(CommandBehavior.CloseConnection);
return mysqlread;
}
#endregion