vb怎么连接mysql数据库代码

Imports MySql.Data.MySqlClient

Public Class Form1
    Dim conn As MySqlConnection
    Dim cmd As MySqlCommand
    Dim sql As String

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        ' 连接MySQL数据库
        conn = New MySqlConnection()
        conn.ConnectionString = "server=数据库服务器地址;user id=用户名;password=密码;database=数据库名称"

        Try
            conn.Open()
            MessageBox.Show("连接成功！")
        Catch ex As Exception
            MessageBox.Show("连接失败：" & ex.Message)
        End Try
    End Sub

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        ' 执行SQL语句
        sql = "SELECT * FROM 表名"
        cmd = New MySqlCommand(sql, conn)

        Try
            Dim reader As MySqlDataReader = cmd.ExecuteReader()
            While reader.Read()
                ' 处理查询结果
                Dim data As String = reader.GetString("字段名")
                MessageBox.Show(data)
            End While
            reader.Close()
        Catch ex As Exception
            MessageBox.Show("查询失败：" & ex.Message)
        End Try
    End Sub

    Private Sub Form1_FormClosing(sender As Object, e As FormClosingEventArgs) Handles MyBase.FormClosing
        ' 关闭数据库连接
        conn.Close()
    End Sub
End Class