$re = '/\([`\s]*([a-z0-9_\$]+)[`\s]*,[`\s]*([a-z0-9_\$]+)[`\s]*\)/i';
$str = 'UNIQUE INDEX `id` (`id`)
UNIQUE INDEX `name` (`name`,`id`)
UNIQUE INDEX test (trt,edw)
UNIQUE INDEX `test2`( `ewe` , wewe )
UNIQUE INDEX `test2`( `ewe` , wewe, mary, stewe )';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php