Calling a Oracle procedure inside ROR

Hi all,auppose I have the following procedure:
CREATE OR REPLACE Procedure Calc_All_Diarias(Pviagem In Number,
Pcompl In Varchar2)
I´m trying to call it this way:
x = ActiveRecord::Base.connection.execute( “exec calc_all_diarias

If I put the statement directly into the PL/SQL Developer it runs just
fine,but in ROR I´m receiving a "Invalid SQL Statement"error.What am I
doing wrong?

Rafael R.