Re: [PHP] Case Insensitive Searching?

At 22:24 23.05.2003, Ben Schneider said:
--------------------[snip]--------------------
>I am working on a project where I am creating a PHP front end to a
>Postgres database. The schema is new but the data is old. Meaning I had to
>convert the data from the old Informix DB.
>
>Anyway all of the existing data is in all upper case. However new data
>going in will be in both upper and lower case.(As requested by the customer.)
>
>So the question is, how do I perform a case insensitive search? Is there a
>DB setting I can set to ignore the case?
>
>If not, then an example of some PHP code that can do this would be of a
>great help.
--------------------[snip]--------------------

There are a couple of ways to do that, it depends on your likes/dislikes as
well as on performance in your specific case.

You could simply use lower() or upper() in your query constraints:
.... WHERE lower(column_name) = lower('search_value')

Use the ILIKE operator (case insensitive LIKE):
.... WHERE column_name ILIKE '%search_value%'

However I did some timings and noticed that ILIKE is appox. 10 times slower
than LIKE. Maybe a problem on my side, but... LIKE constructs usually tend
to NOT use indexes.

To have an index at hand for a lower() search, create an index using
lower() values:
CREATE INDEX id_lower_content ON mytable(lower(column_name))

--
>O Ernest E. Vogelsinger
(\) ICQ #13394035
^ http://www.vogelsinger.at/