Re: most idiomatic way to iterate over an associative array?

On May 7, 4:37�pm, "stephen O'D" <stephen.odonn..._at_gmail.com> wrote:
> On May 7, 5:28 pm, Mark D Powell <Mark.Pow..._at_eds.com> wrote:
>
>
>
>
>
> > On May 7, 4:07 am, Robert Klemme <shortcut..._at_googlemail.com> wrote:
>
> > > On May 7, 6:51 am, m..._at_pixar.com wrote:
>
> > > > This is what I'm doing now... is there a better way?
> > > > It would be great if there were some construct such
> > > > as 'for i in x begin ... end;'
>
> > > > � � i := x.first;
> > > > � � loop
> > > > � � � � dbms_output.put_line(i);
> > > > � � � � exit when i = x.last;
> > > > � � � � i := x.next(i);
> > > > � � end loop;
>
> > > > Many TIA!
> > > > Mark
>
> > > This will break for empty collections. �You can do
>
> > > SQL> set serverout on
> > > SQL> DECLARE �TYPE population_type IS TABLE OF NUMBER INDEX BY
> > > VARCHAR2(64);
> > > � 2 � �continent_population population_type;
> > > � 3 � �which VARCHAR2(64);
> > > � 4 �BEGIN
> > > � 5 � �dbms_output.put_line('-----------');
> > > � 6
> > > � 7 � �which := continent_population.FIRST;
> > > � 8 � �while which is not null loop
> > > � 9 � � �dbms_output.put_line(which || ' -> ' ||
> > > continent_population(which));
> > > �10 � � �which := continent_population.NEXT(which);
> > > �11 � �end loop;
> > > �12
> > > �13 � �dbms_output.put_line('-----------');
> > > �14
> > > �15 � �continent_population('Australia') := 30000000;
> > > �16 � �continent_population('Antarctica') := 1000; -- Creates new
> > > entry
> > > �17 � �continent_population('Antarctica') := 1001; -- Replaces
> > > previous value
> > > �18
> > > �19 � �which := continent_population.FIRST;
> > > �20 � �while which is not null loop
> > > �21 � � �dbms_output.put_line(which || ' -> ' ||
> > > continent_population(which));
> > > �22 � � �which := continent_population.NEXT(which);
> > > �23 � �end loop;
> > > �24
> > > �25 � �dbms_output.put_line('-----------');
> > > �26 �END;
> > > �27 �/
> > > -----------
> > > -----------
> > > Antarctica -> 1001
> > > Australia -> 30000000
> > > -----------
>
> > > PL/SQL procedure successfully completed.
>
> > > SQL>
>
> > > Cheers
>
> > > robert
>
> > > seehttp://download.oracle.com/docs/cd/B19306_01/appdev.102/b14261/collec......
>
> > I think I would consider the For I in 1..n construct
>
> > UT1 > l
> > � 1 �declare
> > � 2 �type t_array is table of varchar2(10) index by binary_integer;
> > � 3 �t_list � t_array;
> > � 4 �begin
> > � 5 �t_list(1) := 'one';
> > � 6 �t_list(2) := 'two';
> > � 7 �t_list(3) := 'three';
> > � 8 �t_list(4) := 'four';
> > � 9 �t_list(5) := 'five';
> > �10 �for I in 1..t_list.last loop
> > �11 � �dbms_output.put_line(t_list(I));
> > �12 �end loop;
> > �13* end;
> > UT1 > /
> > one
> > two
> > three
> > four
> > five
>
> > PL/SQL procedure successfully completed.
>
> > Again as Robert warned in his solution the array should not be empty.
>
> > HTH -- Mark D Powell --
>
> I am fairly sure if you do
>
> for i in 1 .. v_array.count loop
> � null;
> end loop;
>
> It will happily handle an empty array (don't have access to Oracle
> right now to check).- Hide quoted text -
>
> - Show quoted text -

Your are probably correct. My quick test failed however using table.count instead of table.last like I did would probably be a better idea and would be worth testing. It has been over 3 years since I wrote any PL/SQL code worth mentioning. After posting I though I should have tested table.first .. table.last also. Maybe tomorrow I will find some spare time.

• Mark D Powell --