title: Can't retrieve data with dot symbol from sql database
body: <p>In my project (vb.net) I store the ip address of a website in a table with column of type <code>nvarchar</code>. But I can't retrieve it from the table. I wonder if its a problem with "dot" symbol. Please help.</p>
  
  <p>This is the command that I use</p>
  
  <pre><code> query = "select *from restricted_sites where site_address='" + webip + "'"
  </code></pre>
  
  <p><code>webip</code> is the ip address of web site.</p>
  
  <p><code></p>
  
  <pre><code>Imports System.Data.SqlClient
  Imports System.Net
  Public Class restrict
      Private Sub clear_button_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles clear_button.Click
          site_TextBox1.Text = ""
          addr_TextBox1.Text = ""
      End Sub
      Private Sub submit_button_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles submit_button.Click
          Dim connectionstr As String
          Dim query As String
          Dim conn As SqlConnection
          Dim cmd As SqlCommand
          Dim webip As String
          Dim hostname As IPHostEntry = Dns.GetHostByName(addr_TextBox1.Text)
          Dim ip As IPAddress() = hostname.AddressList
          Try
              webip = ip(0).ToString
              connectionstr = "Data Source=.\SQLEXPRESS;AttachDbFilename=C:\Program Files\Microsoft SQL Server\MSSQL10.SQLEXPRESS\MSSQL\DATA\URLTrack.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True"
              conn = New SqlConnection(connectionstr)
              conn.Open()
              query = "insert into restricted_sites values('" + site_TextBox1.Text + "','" + webip + "')"
              cmd = New SqlCommand(query, conn)
              cmd.ExecuteNonQuery()
              MsgBox("Website added for restriction", MsgBoxStyle.Information)
              conn.Close()
          Catch ex As SqlException
          End Try
      End Sub
  End Class
  </code></pre>
  
  <p></code></p>
  
  <pre><code>Private Sub Combox1_KeyPress(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles Combox1.KeyPress
          If e.KeyChar = Convert.ToChar(Keys.Enter) Then
              Dim connectionstr As String
              Dim query As String
              Dim cmd As SqlCommand
              Dim reader As SqlDataReader
              Dim conn As SqlConnection
              Dim url As String = ""
              Dim webip As String
              Dim hostname As IPHostEntry = Dns.GetHostByName(Combox1.Text)
              Dim ip As IPAddress() = hostname.AddressList
              webip = ip(0).ToString
              connectionstr = "Data Source=.\SQLEXPRESS;AttachDbFilename=C:\Program Files\Microsoft SQL Server\MSSQL10.SQLEXPRESS\MSSQL\DATA\URLTrack.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True"
              conn = New SqlConnection(connectionstr)
              conn.Open()
              query = "select * from restricted_sites where site_address='" + webip + "'"
              cmd = New SqlCommand(query, conn)
              reader = cmd.ExecuteReader
              While (reader.Read())
                  url = reader(2)
              End While
              reader.Close()
              MsgBox(url, MsgBoxStyle.Information)
              If webip &lt;&gt; url Then
                  AxWebBrowser1.Navigate(Combox1.Text)
                  Combox1.Text = AxWebBrowser1.LocationURL
              Else
                  MsgBox("This Web Page is Restricted.Contact the ADMIN for Further Info", MsgBoxStyle.Critical)
              End If
          End If
          If e.KeyChar = Convert.ToChar(Keys.Escape) Then
              AxWebBrowser1.Stop()
          End If
      End Sub
  </code></pre>
  
  <p>The second code is the comparing part.
  query = "select * from restricted_sites where site_address='" + webip + "'"
  this code is the problem.
  This is my code for restricting web sites through matching with ip address stored in database,when the url is being navigated.</p>