At 14:16 04/09/03, Colin Wetherbee wrote:
Hardy Merrill said:
> Kristian Nielsen [EMAIL PROTECTED] wrote:
>> Could you briefly explain what an INSERT/UPDATE cursor is?
>
> I also don't know what an INSERT/UPDATE cursor is.

I know how a SELECT cursor works, but INSERT/UPDATE seems voodoo to me.
My current PostgreSQL session doesn't seem to like it too much, either.
It can't parse INSERT or UPDATE after CURSOR FOR.  I looked in my
PostgreSQL reference book, and I don't see a thing on it.

Would anyone care to elaborate on the INSERT/UPDATE cursor?  I can't seem
to wrap my head around how it would work, seeing as there wouldn't really
be a result set to traverse, like there is with a SELECT cursor.

<teachGrandmother> SELECT blah FOR UPDATE { OF col, col, ... }

Prepare and execute
read cursor_id from statement handle
Fetch Loop {
processing
UPDATE table SET col = blah WHERE CURRENT OF cursor_id
or
DELETE FROM table blah WHERE CURRENT OF cursor_id
}

(aka POSITIONED UPDATE | DELETE - See 'A Guide to The SQL Standard' 4th Edition, CJ Date with Hugh Darwen)

INSERT cursor is a contradiction of terms
</teachGrandmother>

HTH
--
MarkT


========================= E M Thornber CEng MIEE Enchanted Systems Limited Software Toolsmiths +44 (0) 1503 272097




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