Forum OpenACS Development: help cursor+decode+ places package

Posted by Rafael Calvo on
apologies for the inexperienced question, there are a couple of things I am not sure how to do here:
  • cursor
  • decode
  • this package address-book depends on places. As far as I can see it is only used in this piece of code and a few times in the www dir. I read in the status document that we were looking to dump 'places', how do I do in this cases?
    cursor address_is_orphan_p_cursor (address_id in
pl_addresses.address_id%TYPE) is
      select decode(count(*),0,''t'',''f'') from place_element_map
where place_id = address_is_orphan_p_cursor.address_id;
    v_address_is_orphan_p char(1);
    cursor subplace_rel_cursor (address_id in
pl_addresses.address_id%TYPE) is
      select sr.rel_id
        from subplace_rels sr,
 	    acs_rels ar
       where ar.rel_id = sr.rel_id
 	and ar.object_id_two = subplace_rel_cursor.address_id;
    v_rel_id subplace_rels.rel_id%TYPE;
Posted by Andrew Piskorski on
Rafeael, I wasted a couple days fooling with Addressbook and Places a
few months ago.  I don't have any of the code in front of me, but as I
recall, the Addressbook package either used an Address object type
provided by the Places package, or it provided it's own.  I seem
remember that it used one provided by Places, in which case you're
going to have to gut that out and put somethin simpler of your own
into Addressbook.

If that cursor address_is_orphan_p_cursor really is just checking for
"orphan" address places in the Places tree, then you probably don't
need it at all!

Posted by Dan Wickstrom on
To port this, you really need to look at the original context of its usage. In the example you've given, the cursors are easily replaced with simple selects. The original code:

      -- Check if the address is an orphan
       open address_is_orphan_p_cursor(address_id => v_addresses_located_row.address_id);
       fetch address_is_orphan_p_cursor into v_address_is_orphan_p;
       close address_is_orphan_p_cursor;
       if v_address_is_orphan_p = 't' then

	-- Delete the address's subplace_relation
	 open subplace_rel_cursor(address_id => v_addresses_located_row.address_id);
	 fetch subplace_rel_cursor into v_rel_id;
	 if not subplace_rel_cursor%NOTFOUND then
	 end if;
	 close subplace_rel_cursor;
	-- Delete the address itself

       end if;

Can be replaced with:

        count(*) = 0 
        place_id = v_addresses_located_row.address_id;

      if v_address_is_orphan_p then
          subplace_rels sr, acs_rels ar
          ar.rel_id = sr.rel_id
          ar.object_id_two = v_addresses_located_row.address_id;
        if FOUND then
          PERFORM subplace_rel__delete(v_rel_id);
        end if;

        PERFORM pl_address__delete(v_addresses_located_row.address_id);
      end if;

In addition, v_address_is_orphan_p needs to change from char(1) to boolean. Notice that the decode(... statement was replaced with select count(*) = 0. This evaluates to either 't' or 'f' depending on the value of count(*). This is a short-cut for converting decodes that evaluate to a simple boolean values. For more complex decodes, you need to use a case statement to port a decode statement. Something like:

        case when count(*) = 0 then 't' 
             when count(*) = 3 then 't' 
                               else 'f' end into v_foo
The above case statement returns true values for counts of 0 and 3 and it is equivalent to decode(count(*),0,'t',3,'t','f').
Posted by Jon Griffin on
Please don't use places.

It is deprecated and not going to be ported. Address book needs to be re-written to support acs-reference which is available by cvs.

places was a monstsrosity that should be forgotten.

Posted by Don Baccus on
Jon's right.  My status sheet entry says "we hope to get rid of places" but doesn't make a definitive statement.  I'll fix that.

Jon's got his acs-references package "95% complete" or something like that (Jon?) and we want to start using that.  It's certainly far enough along for you to do so even though it's not 100% done.  I'm sure he'll be more than willing to answer questions via e-mail, etc.

Posted by Rafael Calvo on

I have almost all the data model ported. This was the last function and I will try to replace the calls to places with acs-references (that I haven't looked at).