vb.net求助往数据库里添加数据失败

Imports System.Data.SqlClient
Public Class register
Dim cn As New SqlConnection("Data Source=.;Initial Catalog=parkinglot;Integrated Security=true;")
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
cn.Open()
Dim cmd As New SqlCommand("insert into users(username,password,email)values('" & TextBox1.Text & "','" & TextBox2.Text & "','" & TextBox3.Text & "')", cn)
End Sub
End Class
运行之后没有报错，但是数据库里面就是没有新增记录
初学数据库求大神指点~谢谢

Dim cmd As New SqlCommand("insert into users(username,password,email)values('" & TextBox1.Text & "','" & TextBox2.Text & "','" & TextBox3.Text & "')", cn)
后面加上
cmd.ExecuteNoQuery