RE: [PHP-DB] Counting Number of Instances in a One2Many Relationships
| From: | Craig Vincent | Date: | Tue, 24 Jul 2001 14:50:41 +0000 |
| Subject: | RE: [PHP-DB] Counting Number of Instances in a One2Many Relationships | ||
| References: | 1 | Groups: | php.db |
| Request: | Send a blank email to php-db+get-10710@lists.php.net to get a copy of this message | ||
<snip>
> I'd like a simple query to determine how MANY books in a
> database are released by A publisher.
[...]
> The relevant table's here:
> Suggestions are appreciated!
SELECT publisherID,count(*) FROM WLPbib GROUP BY publisherID;
</snip>
That query is only acceptable if you want a list of all the publishers and
the books each of them produced. If you only want the results for one
publisher
SELECT count(*) FROM WLPbib WHERE publisherID = '$idtoquery'
should be more than acceptable
Either way you may want to consider indexing this table if you have a fairly
large number of records or will be doing a fair number of these queries on a
regular basis
Sincerely,
Craig Vincent