"Real" world example

fct.sql

CREATE OR REPLACE FUNCTION normalize(to_handle varchar) RETURNS varchar STRICT
AS $$
BEGIN
 return lower(regexp_replace(handle,'[^[:alnum:]]','', 'g'));
END;
$$ LANGUAGE plpgsql IMMUTABLE;


CREATE TABLE taxonomy ( id integer, name varchar, name_normalized varchar);

/** A trigger that does taxonomy.name_normalized := normalize(name); on insert and update; ***/

File.php

<?php
/** search for Taxon **/

$sth = $dbh->prepare("SELECT id, name
    FROM taxonomy 
    WHERE name_normalized like normalize(?) || '%' ");
$sth->bindValue(1, $_POST['name'], PDO::PARAM_STR);
$sth->execute();
$result = $sth->fetch(PDO::FETCH_ASSOC);