vb连接mysql数据库源码

Imports MySql.Data.MySqlClient

Public Class Form1
    Dim conn As MySqlConnection
    Dim cmd As MySqlCommand

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        '连接MySQL数据库
        conn = New MySqlConnection("server=数据库服务器地址;user id=用户名;password=密码;database=数据库名")
        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 btnInsert_Click(sender As Object, e As EventArgs) Handles btnInsert.Click
        '向数据库插入数据
        Dim sql As String = "INSERT INTO 表名 (字段1, 字段2) VALUES (@value1, @value2)"
        cmd = New MySqlCommand(sql, conn)
        cmd.Parameters.AddWithValue("@value1", txtValue1.Text)
        cmd.Parameters.AddWithValue("@value2", txtValue2.Text)
        Try
            cmd.ExecuteNonQuery()
            MessageBox.Show("插入成功")
        Catch ex As Exception
            MessageBox.Show("插入失败：" & ex.Message)
        End Try
    End Sub

    Private Sub btnQuery_Click(sender As Object, e As EventArgs) Handles btnQuery.Click
        '从数据库查询数据
        Dim sql As String = "SELECT * FROM 表名"
        cmd = New MySqlCommand(sql, conn)
        Dim reader As MySqlDataReader
        Try
            reader = cmd.ExecuteReader()
            While reader.Read()
                '处理查询结果
                Dim value1 As String = reader.GetString("字段1")
                Dim value2 As String = reader.GetString("字段2")
                MessageBox.Show("字段1: " & value1 & ", 字段2: " & value2)
            End While
        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
        If conn.State = ConnectionState.Open Then
            conn.Close()
        End If
    End Sub
End Class