C#链接MySQL

╰+哭是因爲堅強的太久メ 2022-09-18 08:55 183阅读 0赞

//需要添加引用MySql.Data.dll
    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;
    using MySql.Data.MySqlClient;//导入用MySql的包
    namespace LinkMysql
    {
        public partial class Form1 : Form
        {
            TestMysql.SQLHelper helper = new TestMysql.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;
    
    
            }
    
    
    
            private void btnAdd_Click(object sender, EventArgs e)
            {
                string sql = string.Format("insert into userinfo values('{0}','{1}')", "root", "admin");
                int i = helper.AddDelUpdate(sql);
                if (i > 0)
                {
                    MessageBox.Show("增加成功");
    
                }
    
            }
    
            private void btnExit_Click(object sender, EventArgs e)
            {
                Application.Exit();
            }
        }
    }
    
    
    namespace TestMysql
    {
        public class DBHelper
        {
            /// <summary>
            /// 得到连接对象
            /// </summary>
            /// <returns></returns>
            public MySqlConnection GetConn()
            {
                MySqlConnection mysqlconn = new MySqlConnection("Database='" + "test" + "';Data Source='" + "localhost" + "';User Id='" + "root" + "';Password='" + "admin" + "'");
                return mysqlconn;
            }
        }
    
    
        public class SQLHelper : DBHelper
        {
            /// <summary>
            /// 查询操作
            /// </summary>
            /// <param name="sql"></param>
            /// <returns></returns>
            public DataTable Selectinfo(string sql)
            {
                MySqlConnection mysqlconn = null;
                MySqlDataAdapter sda = null;
                DataTable dt = null;
                try
                {
                    mysqlconn = base.GetConn();
    
                    sda = new MySqlDataAdapter(sql, mysqlconn);
                    dt = new DataTable();
                    sda.Fill(dt);
    
                    return dt;
                }
                catch (Exception)
                {
    
                    throw;
                }
    
            }
    
            /// <summary>
            /// 增删改操作
            /// </summary>
            /// <param name="sql">sql语句</param>
            /// <returns>执行后的条数</returns>
            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;
                }
            
            }
    
    
    
        }
    }