Small script to parse an SQL query into an associative array

query_parse.php

<?php
function parseQueryToArray($query) {
	$twoWordChunks = array('GROUP', 'ORDER');
	$twoWordChunk = '';

	$joinChunks = array('LEFT', 'RIGHT', 'INNER', 'OUTER');
	$joinChunk = '';

	$out = array(
		'SELECT' => null,
		'FROM' => null,
		'JOIN' => null,
		'WHERE' => null,
		'GROUP BY' => null,
		'ORDER BY' => null,
		'HAVING' => null,
		'LIMIT' => null
	);

	$tempKey = '';
	$tempValues = '';

	$isJoin = false;
	$chunks = explode(' ', $query);
	foreach ($chunks as $chunk) {
		if (in_array($chunk, $twoWordChunks)) {
			$twoWordChunk = $chunk;
			continue;
		}

		if (in_array($chunk, $joinChunks)) {
			$joinChunk = $chunk;
			continue;
		}

		if ($twoWordChunk) {
			$chunk = $twoWordChunk . ' ' . $chunk;
			$twoWordChunk = '';
		}

		if (array_key_exists($chunk, $out)) {
			if ($tempKey && $tempValues) {
				if (!$out[$tempKey]) {
					$out[$tempKey] = $isJoin ? array() : '';
				}

				if ($isJoin) {
					$out[$tempKey][] = implode(' ', $tempValues);
				} else {
					$out[$tempKey] .= implode(' ', $tempValues);
				}
			}
			$tempKey = $chunk;
			$tempValues = array();
			$isJoin = $tempKey == 'JOIN' ? 1 : 0;
			continue;
		} else {
			if ($joinChunk) {
				$chunk = $joinChunk . ' ' . $tempKey . ' ' . $chunk;
				$joinChunk = '';
			}
			$tempValues[] = $chunk;
		}
	}

	if (!$out[$tempKey]) {
		$out[$tempKey] = $isJoin ? array() : '';
	}

	if ($isJoin) {
		$out[$tempKey][] = implode(' ', $tempValues);
	} else {
		$out[$tempKey] .= implode(' ', $tempValues);
	}
	return $out;
}

function injectSelectAndJoinIntoQuery($query, $selectToAdd, $joinToAdd) {
  $queryArray = parseQueryToArray($query);

	$out = array();
	$out[] = 'SELECT ' . implode(',', $queryArray['SELECT']) . ' ' . $selectToAdd;
	$out[] = 'FROM ' . implode(' ', $queryArray['FROM']);
	if (count($queryArray['JOIN'])) $out[] = implode(' ', $out['JOIN']) . ' ' . $joinToAdd;
	if ($queryArray['WHERE']) $out[] = 'WHERE ' . $queryArray['WHERE'];
	if ($queryArray['GROUP BY']) $out[] = 'GROUP BY ' . $queryArray['GROUP BY'];
	if ($queryArray['ORDER BY']) $out[] = 'ORDER BY ' . $queryArray['ORDER BY'];
	if ($queryArray['HAVING']) $out[] = 'HAVING ' . $queryArray['HAVING'];
	if ($queryArray['LIMIT']) $out[] = 'LIMIT ' . $queryArray['LIMIT'];

	return implode(' ', $out);
}