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* simple update from select ??
@ 2005-03-07 12:28 Gary Stainburn <gary.stainburn@ringways.co.uk>
0 siblings, 1 reply; 2+ messages in thread
From: Gary Stainburn @ 2005-03-07 12:28 UTC (permalink / raw)
To: pgsql-sql
Hi folks
I've got a table of pieces of equipment.
One piece of equipment may be owned by another piece of equipment, and
may own multiple other pieces.
To hold the relationship I have a piece_pieces table holding the owner
(pp_id) part id and the owned part ids (pp_part).
I'v realised I can store this within the original table so I've added an
owner attribute. I need to now populate this now from the other table,
but I can't work out how.
I've got pieces table
p_id -- part id
p_owner -- new owner attribute
piece_pieces table
pp_id -- id of owner
pp_part -- id of owned
--
Gary Stainburn
This email does not contain private or confidential material as it
may be snooped on by interested government parties for unknown
and undisclosed purposes - Regulation of Investigatory Powers Act, 2000
^ permalink raw reply [nested|flat] 2+ messages in thread
* Re: simple update from select ??
@ 2005-03-07 14:44 Gary Stainburn <gary.stainburn@ringways.co.uk>
parent: Gary Stainburn <gary.stainburn@ringways.co.uk>
0 siblings, 0 replies; 2+ messages in thread
From: Gary Stainburn @ 2005-03-07 14:44 UTC (permalink / raw)
To: pgsql-sql
On Monday 07 March 2005 12:28 pm, you wrote:
> Hi folks
>
> I've got a table of pieces of equipment.
> One piece of equipment may be owned by another piece of equipment,
> and may own multiple other pieces.
>
> To hold the relationship I have a piece_pieces table holding the
> owner (pp_id) part id and the owned part ids (pp_part).
>
> I'v realised I can store this within the original table so I've added
> an owner attribute. I need to now populate this now from the other
> table, but I can't work out how.
>
> I've got pieces table
>
> p_id -- part id
> p_owner -- new owner attribute
>
> piece_pieces table
>
> pp_id -- id of owner
> pp_part -- id of owned
For my own future reference as much as anything, here's the required
statement, which is a syntactically corrected version of a suggestion
by Sean Davis
update pieces set p_owner=piece_pieces.pp_id from piece_pieces where
piece_pieces.pp_part=pieces.p_id;
Under Sean's suggestion I did this inside a transaction block so I could
check that it did what I wanted.
--
Gary Stainburn
This email does not contain private or confidential material as it
may be snooped on by interested government parties for unknown
and undisclosed purposes - Regulation of Investigatory Powers Act, 2000
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2005-03-07 12:28 simple update from select ?? Gary Stainburn <gary.stainburn@ringways.co.uk>
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