¿Cómo usar datos de Oracle para calcular en C#?

OracleConnection conn = new OracleConnection("Your Connection string");
conn.Open();
DataSet dataSet = new DataSet();
OracleCommand cmd = new OracleCommand(
    "SELECT * FROM TABLE1 t inner join TABLE2 t1 on t.code_value = t1.code_value"
);
cmd.CommandType = CommandType.Text;
cmd.Connection = conn;

using (OracleDataAdapter dataAdapter = new OracleDataAdapter())
{
  dataAdapter.SelectCommand = cmd;
  dataAdapter.Fill(dataSet);
}

DataTable dt = ds.Tables[0];
//loop through table's rows/columns
var myVal = ParseToDouble(dt.Rows["value"].ToString());
var checkRule = ParseToDouble(dt.Rows["check_rule"].ToString());

if(myVal < checkRule)
   doSomething();


public double ParseToDouble(string s)
{
    return decimal.Parse( s.TrimEnd('%') ) / 100M;
}