Path: utzoo!utgpu!water!watmath!clyde!burl!codas!killer!jfh
From: jfh@killer.UUCP (John Haugh)
Newsgroups: comp.databases
Subject: Re: Informix Brain Teaser
Summary: Can't be done ...
         ... using ACE.
Message-ID: <2830@killer.UUCP>
Date: 13 Jan 88 17:31:18 GMT
References: <2678@slovax.UUCP>
Distribution: na
Organization: Big "D" Home for Wayward Hackers
Lines: 53

In article <2678@slovax.UUCP>, flak@slovax.UUCP (Dan Flak) writes:
> Here's a brain teaser for you folks using Informix 3.30. (I can't
> validate SQL since I don't have it).
> 
> The schema looks like:
> 
>     database foo
> 
>     file family
> 
>     field name   type character 20 index primary
>     field parent type character 20 index dups.
> 
>     end
[ stuff deleted ]
> The challenge:
> 
>     Write a progam using ACE and/or C which will accept as its
> first argument the name of any ancestor, and produce a list of all
> descendants for as many generations as are loaded in the database.
> --
> Dan Flak-R & D Associates,3625 Perkins Lane SW,Tacoma,Wa 98499,206-581-1322

This is basically impossible in ACE.  You can get N generations using N
read statements.  Watch -

database people end

define param[1] person type character length 20 end

read into children parent, child = name where parent = person end

{ now I have the first generation }

read into grandchildren children, grandchild = name
	joining children.child = optional parent

{ now I have the second }

sort by parent, child, grandchild end

format every record end

To get the third generation you need a third read.  It would look similiar
to the second, except, the new field would be aliased to `greatgrandchild'.
Just remember the 50 character limit on field names ;-).

- John.
-- 
John F. Haugh II                  SNAIL:  HECI Exploration Co. Inc.
UUCP: ...!ihnp4!killer!jfh                11910 Greenville Ave, Suite 600
"Don't Have an Oil Well? ...              Dallas, TX. 75243
 ... Then Buy One!"                       (214) 231-0993 Ext 260