vb.net連接SQL数据库

'導入命名空間
Imports System.Data.SqlClient

Public Class Form126
'定義變量
Dim Sql As String
Dim Sqlado As SqlConnection '连接数据库
Dim CmdVB As SqlCommand '对数据源执行SQL命令并返回数据
Dim drVB As SqlDataReader '读取和处理数据源的数据

'打开ADO連線
Public Sub OpenADO()
Sqlado = New SqlConnection("Password=密碼;Persist Security Info=True;User ID=sa;Initial Catalog=VB;Data Source=数据源")
If Sqlado.State = ConnectionState.Closed Then
Sqlado.Open()
End If
CmdVB = New SqlCommand(Sql, Sqlado)
drVB = CmdVB.ExecuteReader()
End Sub

'关闭ADO連線
Public Sub CloseADO()
drVB.Close()
If Sqlado.State = ConnectionState.Open Then
Sqlado.Close()
End If
End Sub

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Sql = ("Select A1 From Table1 ")
OpenADO() '打开ADO連線
drVB.Read()
TextBox1.Text = drVB.Item(0)
CloseADO() ' '关闭ADO連線

End Sub
End Class