André
> Sorry, my english sentence was imprecise. :) I want the count of all
> sub-entries AND THEIR sub-sub-entries.
Example:
A
/ \
B C
/ \
D E
\
F
So I want to know that C has 3 sub-nodes.
Aha! I thought it seemed like an easy question ;-)
As far as i know, the only way to do this is one of the methods you suggested -
recursively adding up, or storing a count which is updated on insert/delete
operations.
--Rob
> -----Ursprüngliche Nachricht-----
> Von: Rob Desbois [mailto:[EMAIL PROTECTED]
> Gesendet: Mittwoch, 27. September 2006 15:48
> An: André Hänsel; mysql@lists.mysql.com
> Betreff: re: Count of children
>
> André,
>
> Your sentence 'I want the count of all sub-entries for a
> specific entry' converts straight into SQL:
>
> 'I want'
> SELECT
> the count of all entries
> COUNT(*) FROM myTable
> with a specific parent
> WHERE parent_id = 5
>
> You've missed one of the major benefits of SQL - it's
> designed to read like an English sentence!
> --Rob
>
>
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<
---------- Original Message ----------
FROM: André Hänsel<[EMAIL PROTECTED]>
TO: "'Rob Desbois'" <[EMAIL PROTECTED]>
DATE: Wed, 27 Sep 2006 16:00:25 +0200
SUBJECT: AW: Count of children
Sorry, my english sentence was imprecise. :) I want the count of all
sub-entries AND THEIR sub-sub-entries.
Example:
A
/ \
B C
/ \
D E
\
F
So I want to know that C has 3 sub-nodes.
> -----Ursprüngliche Nachricht-----
> Von: Rob Desbois [mailto:[EMAIL PROTECTED]
> Gesendet: Mittwoch, 27. September 2006 15:48
> An: André Hänsel; mysql@lists.mysql.com
> Betreff: re: Count of children
>
> André,
>
> Your sentence 'I want the count of all sub-entries for a
> specific entry' converts straight into SQL:
>
> 'I want'
> SELECT
> the count of all entries
> COUNT(*) FROM myTable
> with a specific parent
> WHERE parent_id = 5
>
> You've missed one of the major benefits of SQL - it's
> designed to read like an English sentence!
> --Rob
>
>
> ______________________________________________________________________
> This email has been scanned by the MessageLabs Email Security System.
> For more information please visit http://www.messagelabs.com/email
> ______________________________________________________________________
>
> --
> MySQL General Mailing List
> For list archives: http://lists.mysql.com/mysql
> To unsubscribe:
> http://lists.mysql.com/[EMAIL PROTECTED]
>
______________________________________________________________________
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For more information please visit http://www.messagelabs.com/email
______________________________________________________________________
______________________________________________________________________
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