Updating Column In A Dataset Not Working

Hi all,

I'm trying to update various rows in my DB with a new value once an action occurs.  I am using the following code which does not throw any exceptions, but also does not change the values.  Can someone steer me in the right direction?

public static void ChangeRefCode()

{

SqlConnection dbConn = new SqlConnection(ConnectDB.getConnectString());

SqlDataAdapter dataAdapt = new SqlDataAdapter("Select * from Posting",dbConn);



DataSet ds = new DataSet();



SqlCommandBuilder sqBuilder = new SqlCommandBuilder(dataAdapt);

dataAdapt.Fill(ds, "Posting");

foreach (DataRow dr in ds.Tables["Posting"].Rows)

{

dr["ref_code"] = DateTime.Today.Ticks + "-" + dr["poster"].ToString();

}

try

{

dataAdapt.Update(ds, "Posting");

}

catch (Exception ex)

{

ex.ToString();

}

finally

{

dbConn.Close();

}

}