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Re: composite objects
3+ messages / 3 participants
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* composite objects
@ 1991-06-25 23:31 Gregory Klein <klein@imasun.lbl.gov>
  1991-06-25 16:46 ` Re: composite objects Mike Olson <mao@postgres.Berkeley.EDU>
  0 siblings, 1 reply; 3+ messages in thread

From: Gregory Klein @ 1991-06-25 23:31 UTC (permalink / raw)
  To: legacy

In the Postgres tutorial, the following composite object was defined:

create EMP(name=c12,salary=float8,age=int4,dept=c12,manager=EMP)

and attributes were appended to the object using

append to EMP (name="Sam",salary=1000,age=40,dept="shoe",
manager=mgr-lookup("shoe"))

where mgr-lookup was defined as the function by

define function mgr-lookup(c12) returns EMP as
retrieve (EMP.all) where EMP.name=DEPT.manager and DEPT.name=$1

Since Postgres 2.1 does not appear to be able to define this sort of
function, is there a way to populate composite objects?

Thanks,
Greg Klein



^ permalink  raw  reply  [nested|flat] 3+ messages in thread

* Re: composite objects
  1991-06-25 23:31 composite objects Gregory Klein <klein@imasun.lbl.gov>
@ 1991-06-25 16:46 ` Mike Olson <mao@postgres.Berkeley.EDU>
  0 siblings, 0 replies; 3+ messages in thread

From: Mike Olson @ 1991-06-25 16:46 UTC (permalink / raw)
  To: legacy

here's a way to make this happen; how it works should be clear from the
example.

	create EMP (name = char16, salary = int4, mgr_name = char16)

	define postquel function manager (EMP) returns EMP is
	    retrieve (e.all) from e in EMP where e.name = current.mgr_name

the 'define postquel function' declares a method on class EMP and adds a
virtual column, 'manager', to the class.  this isn't perfect, but will
do what you want at the cost of an additional key stored in each EMP
instance.

					mike olson
					postgres research group
					uc berkeley
					mao@postgres.berkeley.edu



^ permalink  raw  reply  [nested|flat] 3+ messages in thread

* Composite Objects
@ 1994-07-13 12:13 Paul Waine <P.Waine1@lut.ac.uk>
  0 siblings, 0 replies; 3+ messages in thread

From: Paul Waine @ 1994-07-13 12:13 UTC (permalink / raw)
  To: legacy


Hi,

	I was wondering what the situation was with regard to composite object
in version 4.2.  Are they still supported via function definition or can they
be directly specified ? Is the situation the same with Illustra ?

Thanks in Advance 
Paul

     +--------------------------------------------------------------------+
     |Paul Waine	         		E-mail P.Waine1@lut.ac.uk |
     |Department of Manufacturing Engineering                             |
     |University of Technology, Loughborough, Leics, LE11 3UE, UK         |
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^ permalink  raw  reply  [nested|flat] 3+ messages in thread

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Thread overview: 3+ messages (download: mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
1991-06-25 23:31 composite objects Gregory Klein <klein@imasun.lbl.gov>
1991-06-25 16:46 ` Mike Olson <mao@postgres.Berkeley.EDU>
1994-07-13 12:13 Composite Objects Paul Waine <P.Waine1@lut.ac.uk>

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