using System;
using System.Data;
using System.Data.OracleClient;

……

protected System.Web.UI.WebControls.DataGrid DataGrid1;
protected System.Web.UI.WebControls.DataGrid DataGrid2;

……

private void BindData()
{
   string connString = "User ID=XXXX;Password=XXXXX;Data Source=XXXX";
   string Ssql = "SELECT * FROM TABLE1; SELECT * FROM TABLE2";
   OracleConnection Conn = new OracleConnection(connString);
   OracleDataAdapter Da = new OracleDataAdapter(Ssql, Conn);
   DataSet Ds = new DataSet();
   Da.Fill(Ds);

   DataGrid1.DataSource = Ds.Tables[0];
   DataGrid1.DataBind();
   DataGrid2.DataSource = Ds.Tables[1];
   DataGrid2.DataBind();
}