Comments on: PHP Mysql tips

By: Tom

Tom — Fri, 29 Feb 2008 13:38:07 +0000

nice tips , i’m using PHP for 5 years but didn’t know all your examples !

I was looking for a lowercase query and found somewhere else :

select * FROM hardware WHERE name regexp ‘$name’

REGEXP isn’t case sensitive. So, problem solved kinda…

By: Adam

Adam — Tue, 13 Nov 2007 16:13:01 +0000

Very nice, I wrote a similar article on TalkPHP.com and I was amazed to find that a lot of programmers who used MySQL were blissfully unaware of such statements - like if statements! How can they not know?

By: Gareth Heyes

Gareth Heyes — Sun, 02 Sep 2007 17:14:36 +0000

ooooo ya got me LOL

ENDSARCASM.

By: asd

asd — Sun, 02 Sep 2007 16:55:17 +0000

phpinfo();

By: Gareth Heyes

Gareth Heyes — Wed, 08 Aug 2007 15:45:24 +0000

Yep performance test everything because it can vary between datasets a lot, I found some things a lot faster than others but you might not get the same results based on your data so keep that in mind. I’m glad the blog helped

By: Solidus Obscura

Solidus Obscura — Wed, 08 Aug 2007 15:01:08 +0000

Yeah, I did sub-queries a lot in a previous job which is why it just occurred to me, since (1,2,3) is really just like a result set of a sub-query. I actually just did a performance test with a different site I’m working on and found little difference in load times. I’ll have to do more testing (preferably with more concurrent users).

Thanks for all the tips. Of course, I should and will performance test all of the advice, but it’s nice knowing things you didn’t before.

By: Gareth Heyes

Gareth Heyes — Wed, 08 Aug 2007 14:52:31 +0000

Yeah IN is much faster, you can also use it with SUB QUERIES as well. For example SELECT * FROM table1 WHERE Field1 IN (SELECT Field2 FROM table2) worth knowing

By: Solidus Obscura

Solidus Obscura — Wed, 08 Aug 2007 14:27:32 +0000

Dunno if I’ll do an implementation of keywords, especially since most of the content will be random postings. More probable will be keywords on user-posted fanarts/fictions which make more sense to search by keyword instead of full text (which the fields will be of the MEDIUMTEXT variety, and you can’t search the content of an image… yet). I’ll keep the tip in mind (glad I happened upon this post).

The thing with the user levels/groups is that the set I search upon can be a random set. In my example, there can be a set of moderators stored as |1|2|3|, and these are set by an admin through a web-based control panel. They can be unrelated to a group, so to get the usernames of these mods, I’d do a SELECT userid,username FROM user WHERE (userid=1 OR userid = 2 OR userid = 3) ORDER BY username where the “or string” is generated by a function. I was curious if there was a more efficient way of doing this. It just dawned on me that it might be better to do a userid IN (1,2,3)…

By: Gareth Heyes

Gareth Heyes — Wed, 08 Aug 2007 13:03:41 +0000

Yes they can only be applied to CHAR, VARCHAR and TEXT fields as the poster mentioned and with MyISAM tables only. You will notice a huge speed improvement for lots of fields with TEXT columns.

With MEDIUMTEXT fields or bigger I suggest making a indexing program which will only gather keywords of the field and place it in a smaller field thus allowing you to search the keywords instead of the MEDIUMTEXT fields.

More information on FULL TEXT is available here:-
http://dev.mysql.com/doc/refman/5.0/en/fulltext-search.html

By: Solidus Obscura

Solidus Obscura — Wed, 08 Aug 2007 12:51:37 +0000

So you set an index on the text field then, and run that sort of query against them? (Sorry if that sounds silly, I’m just accustomed to using numerical indexes). And, would that work on MEDIUMTEXT fields (According to a previous poster… “Full-text indexes can be used only with MyISAM tables, and can be created only for CHAR, VARCHAR, or TEXT columns.”)? I generally try to use TEXT fields whenever possible, but there are one or two body fields in my db that require the maximum of a MEDIUMTEXT (more than 65535 chars).