- preg_match: documentation ( source)
- print_r: documentation ( source)
<?php
echo '<pre>';
preg_match('/^(LEFT JOIN|RIGHT JOIN|INNER JOIN|JOIN)(?: +)([^ ]+)(?: +)ON(?: +)(.*)$/i', 'JOIN Skill ON Skill.SkillID = EmployeeSkill.SkillID', $matches);
print_r($matches);