title: Update local database all modified data to server database
body: <p>I'm facing a problem when I want to update data from local database to server data, replacing everything that has been modified at local database. I know it might be simple but I got no idea about this, so any help will be appreciate.</p>
  
  <blockquote>
    <p>In my situation, I want to use a button to upload all modified data to
    the server database. Now I'm just using 2 databases at same server to do
    testing.</p>
  </blockquote>
  
  <pre class="lang-vb prettyprint-override"><code>Private Sub btnUp_Click(sender As System.Object, e As System.EventArgs) Handles btnUp.Click
      localconn.ConnectionString = lctext
      serverconn.ConnectionString = sctext
      Try
          localconn.Open()
          serverconn.Open()
          Dim localcmd As New OdbcCommand("select a.acc_id as localid, a.acc_brcid, a.smartcardid, a.acc_created, a.acc_modified as localmodified, b.acd_firstname, b.acd_ic, b.acd_oldic, b.acd_race, b.acd_dob, b.acd_rescity, b.acd_resaddr1, b.acd_telmobile, b.acd_email, b.acd_telwork, b.acd_modified, b.acd_accid from nsk_account a inner join nsk_accountdetail b on a.acc_id = b.acd_accid", localconn)
  
          Dim servercmd As New OdbcCommand("select c.acc_id, c.acc_brcid, a.smartcardid, c.acc_created, c.acc_modified, d.acd_firstname, d.acd_ic, d.acd_oldic, d.acd_race, d.acd_dob, d.acd_rescity, d.acd_resaddr1, d.acd_telmobile, d.acd_email, d.acd_telwork, d.acd_modified, d.acd_accid from nsk_account c inner join nsk_accountdetail d on c.acc_id = d.acd_accid", serverconn)
  
          localcmd.CommandType = CommandType.Text
          Dim rdr As OdbcDataReader = localcmd.ExecuteReader()
          Dim thedatatable As DataTable = rdr.GetSchemaTable()
  
          'localcmd.Parameters.Add("@localid", OdbcType.Int, "a.acc_id")
          'localcmd.Parameters.Add("@localmodified", OdbcType.DateTime, "b.acd_modified")
          Dim localid As String
          Dim localmodi As String
          localcmd.Parameters.AddWithValue("localid", localid)
          localcmd.Parameters.AddWithValue("localmodified", localmodi)
  
          For Each localid In thedatatable.Rows
              Dim calldata As New OdbcCommand("SELECT acc_modified from nsk_account where acc_id ='" + localid + "'", serverconn)
              Dim reader As OdbcDataReader = calldata.ExecuteReader
              txtSDate.Text = reader("acc_modified").ToString
              If localmodi &lt;= txtSDate.Text Then
                  'do nothing, proceed to next data
              Else
                  Dim ACCoverwrite As New OdbcCommand("Update nsk_account SET smartcardid = @mykad, acc_created = @created, acc_modified = @modify WHERE acc_id ='" + localid + "'", serverconn)
                  Dim DEToverwrite As New OdbcCommand("Update nsk_accountdetail SET acd_firstname = @name, acd_ic = @newic, acd_oldic = @oldic, acd_race = @race, acd_dob = @dob, acd_rescity = @city, acd_resaddr1 = @address, acd_telmobile = @phone, acd_email = @email, acd_telwork = @language, acd_modified = @detmodify WHERE acd_accid ='" + localid + "'", serverconn)
                  ACCoverwrite.ExecuteNonQuery()
                  DEToverwrite.ExecuteNonQuery()
              End If
          Next
  
          MessageBox.Show("Upload success", "Error", MessageBoxButtons.OK, MessageBoxIcon.Warning)
  
      Catch ex As Exception
          MessageBox.Show(ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Warning)
      Finally
          localconn.Close()
          serverconn.Close()
      End Try
  End Sub
  </code></pre>
  
  <p>any comment or suggestion will be appreciate.</p>