Passing SQL Query Result into a String

Ankit , vuples help me out to solve my problem posted just

use ExecuteScalar() bcoz it is returning single value try this
string res=Convert.ToString(oc.ExecuteScalar());
it will work.

Hi Behrouz,
  I have another e.g for this : 

string queryString = "Select FName From Emp Where EmpID = 20";
string res="";  
using (OracleConnection connection = new OracleConnection(connectionString))
{
try
  {
    OracleCommand command = new OracleCommand(queryString, connection);
    connection.Open();
    OracleDataReader reader = command.ExecuteReader();
    while (reader.Read())
      {
        res=reader.GetString(0);
      }
   }
catch(Exception ex)
{
MessageBox.Show(ex.Message);
}
finally
{
 // always call Close when done reading.
reader.Close();
connection.Close(); 
}
}