$re = '/CREATE TABLE\s+\'([^\']+)[\s\S]+PRIMARY KEY\(([^,]+),([^\)]+)\)/';
$str = 'CREATE TABLE \'dhcpr_dhcprelayinterface\' (
\'vrId\' integer default 0,
\'ifName\' string ,
PRIMARY KEY(ifName,vrId),
FOREIGN KEY (vrId) REFERENCES \'vr_vr\'(vrId) ON DELETE CASCADE ON UPDATE CASCADE);';
preg_match($re, $str, $matches, PREG_OFFSET_CAPTURE, 0);
// Print the entire match result
var_dump($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