statement_execute_select
Description:
Executes a selection command on the given connection.
This function returns a DataModel resulting from the SELECT statement, or 
        null if an error occurred.
This function is just a convenience function around the statement_execute function.
See the documentation of the statement_execute for information
      about the params list of parameters.
Parameters:
| this | 
           a Connection object.  | 
      
| stmt | 
           a Statement object.  | 
      
| params | 
           a Set object (which can be obtained using 
            get_parameters), or   | 
      
Returns:
| 
           a DataModel containing the data returned by the data source, or   |