vb.net连接SQL出错：索引从0处开始

vb.net连接SQL出错：

源程序如下：
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
  Dim selectclause As String = "select *"
  dim fromclause As String = "from 站点信息"  '用于构成from子句
  Dim whereclause As String = ""
  If Not TextBox1.Text = "" Then
  whereclause += "and 站点名= " + "'" + TextBox1.Text + "'"
  End If
  If Not TextBox2.Text = "" Then
  whereclause += "and 地址= " + "'" + TextBox2.Text + "'"
  End If
  If Not TextBox3.Text = "" Then
  whereclause += "and 站点类型= " + "'" + TextBox3.Text + "'"
  End If

  Dim querystring As String = selectclause + fromclause + whereclause 
  Dim connectionstring As String = "user id="";initial catalog= 站点信息表;data source=localhost"
 
  Dim connection As New SqlConnection(connectionstring)”运行时这句总出错，说是'从索引0初开始，初始化字符串处理异常'“[/color]
  Dim dataadapter As New SqlDataAdapter
  dataadapter.SelectCommand = New SqlCommand(querystring, connection)

  Dim dataset As New DataSet

  Try
  connection.Open()
  dataadapter.Fill(dataset, "站点信息")
  DataGridView1.DataSource = dataset.Tables("站点信息")
  DataGridView1.Focus()

  Catch ex As Exception
  MsgBox(ex.Message)

  End Try

  connection.Close()


  End Sub


------解决方法--------------------------------------------------------
Dim querystring As String = selectclause + fromclause + whereclause

querystring 拼起来后里面确少必要的空格吧 你有没有DEBUG进去看下这个SQL啊？

比如  Dim selectclause As String = "select *"
  dim fromclause As String = "from 站点信息"