Using a PHP variable in an RLIKE regex

Here's a link to the man page.
http://dev.mysql.com/doc/refman/5.7/en/regexp.html

Can you just tell us in plain language what you are trying to achieve?  I'm sure there is a correct syntax, but I don't understand the objective from the example posted here.

Cat4 is one column of a 'Categories" table and I want to return all the records where the Cat4 field contains the word passed in as $term.  I got the '[[:<:]]word[[:>:]]' format from the man page you linked to:


I've also tried backslashing the $ but that doesn't work.

Suggest you construct the RLIKE expression in a separate PHP variable, like this:
http://iconoun.com/demo/temp_steva.php?q=word

<?php // demo/temp_steva.php
/**
 * http://www.experts-exchange.com/questions/28932231/Using-a-PHP-variable-in-an-RLIKE-regex.html#a41501765
 */
error_reporting(E_ALL);
echo '<pre>';

// ACQUIRE THE REQUEST VARIABLE
$q = !empty($_GET['q']) ? $_GET['q'] : NULL;
if ($q)
{
    // BUILD THE REGEX (RLIKE) CLAUSE
    $regex = '[[:<:]]' . $q . '[[:>:]]';
    $query = "SELECT 'a word a' REGEXP $regex";

    var_dump($query);
}

Select allOpen in new window

Thanks Ray for putting that together. Someone else, though,  suggested just putting the variable inside of {}, and it worked!

$term= ($_POST['term']);

"SELECT *
FROM Categories
WHERE Cat4 RLIKE  '[[:<:]]{$term}[[:>:]]'
";

Select allOpen in new window

They weren't able to explain why it worked. I suspect, though,  that the curly braces drew PHP's attention immediately to the enclosed variable so the variable got expanded before anything else was looked at.