Re: SQL in array() ?

I'm not going to comment on array processing techniques, but I suggest you are into a situation where you have to rethink your database design from the point of view of performance and normalization. I don't know how many records you will eventually have, but the key to performance in SQL databases is the effective use of indexes, and queries which match. Even if you have an index on the cat_id field, a query like SELECT * FROM entries WHERE cat_id IN($getcats) forces the database engine into a sequential read of the cat_id field. So you can drop the cat_id field from entries and create a new table entry_cat which has two fields id cat_id Which gives you this query, although I'm a little uncertain about the bracketing of the condition. select entries.id, entries.name, entry.cat_id from entries, entry_cat where (entry_cat.id = 1 || entry_cat.id = 3) (And which, on reflection, may not yield better performance.) All this brings me to the question I should have asked up front. How often will you want to select multiple categories, and will it be done by range (>2 , <=3) or individual items ( 1 and 5 and 7 )? I don't think I've been terribly helpful - Miles At 12:14 PM 7/17/01 +0100, James Holloway wrote:

Hey guys, I saw a post in here the other day that's prompted me to ask this question... Because I can't seem to get the solution mentioned to work. Maybe I'm missing something obvious... Anyway, here goes. I have a list of categories contained in one table, and a list of entries in another. So categories: id name 1 category1 2 category2 3 category3 At the moment, the entries table has a field which contains a field mentioning the category by id, so: entries id cat_id name 1 1 name1 2 1 name2 3 1 name3 The problem is this: I'd like to give some entries more than one category. I attempted to put the category id's into an array. So a row in the revised entries table now looks like this: entries id cat_id name 1 2 name1 2 1,3 name2 3 1 name3 And I'm trying to list from that table with code similar to this: <? $cat[0] = 1; $cat[1] = 3; $getcats = implode(",", $cat); $query = @mysql_query("SELECT * FROM entries WHERE cat_id IN($getcats)")

    or die (mysql_error());

// Get the results ?> I get no errors when executing that code, but I don't get any results back, either...... even though I know there are entries in the table with the category id listed as 1,3 Any ideas? I'm having "one of those days" :) Cheers, James. -- PHP General Mailing List (http://www.php.net/) To unsubscribe, e-mail: php-general-unsubscribe@lists.php.net For additional commands, e-mail: php-general-help@lists.php.net To contact the list administrators, e-mail: php-list-admin@lists.php.net