Searching?

[tekp]

I've been wondering for a while now how search engines work, the ones on individual sites, as opposed to web searches (google, for example).

Is there a specific SQL command to select data from a table that roughly matches a string? Or would you have to extract the data piece by piece and compare it manually using PHP?

Or does it not use sql/php at all...?

Just wondering, as it's bugging me.

[bfsog]

There is the LIKE command..
http://www.htmlite.com/mysql011.php

Or there is the FULLTEXT command

http://www.phpfreaks.com/tutorials/129/0.php

A sample query I have on a page using like is

$query = "SELECT * FROM pages WHERE (title LIKE '%".$v."%' OR title LIKE '".$v."%' OR title LIKE '%".$v."')"; 

The first WHERE means where $v is in the column, the second means where the column starts with $v and the last means when the column ends with $v

Hope this helps.

[Mr C]

Or you could build the sql statement on the fly.

eg if they enter:
flowers AND pots OR weeds

Then you iterate through the text and build the SQL with appropriate LIKE statements seperated by AND OR etc.

[tekp]

Thanks for the response, I'll check out the links when I have more time.

Thanks again