Description
int 
db2_num_rows ( resource stmt )
   Returns the number of rows deleted, inserted, or updated by an SQL
   statement.
  
   To determine the number of rows that will be returned by a SELECT
   statement, issue SELECT COUNT(*) with the same predicates as your
   intended SELECT statement and retrieve the value.
  
   If your application logic checks the number of rows returned by a SELECT
   statement and branches if the number of rows is 0, consider modifying your
   application to attempt to return the first row with one of
   db2_fetch_assoc(), db2_fetch_both(),
   db2_fetch_array(), or db2_fetch_row(),
   and branch if the fetch function returns FALSE.
  
Note: 
    If you issue a SELECT statement using a scrollable cursor,
    db2_num_rows() returns the number of rows returned by
    the SELECT statement. However, the overhead associated with scrollable
    cursors significantly degrades the performance of your application, so if
    this is the only reason you are considering using scrollable cursors,
    you should use a forward-only cursor and either call SELECT COUNT(*) or
    rely on the boolean return value of the fetch functions to
    achieve the equivalent functionality with much better performance.