Added negative lookahead

It is possible to have multiple occurrences of 'as' in a field name.
Use the last occurrence of 'as' when extracting field name.

Tested with following examples:
"WeldCheck"."weld_id"
count(*) as WeldCheck__num_measurements
count(case decision when 2 then 1 else null end) as
WeldCheck__num_failures
avg(cast (WeldMeasurement.surface_indentation as bigint)) as
WeldCheck__avg_indentation
avg(cast (WeldMeasurement.circle_diameter as bigint)) as
WeldCheck__avg_diameter

lib/Cake/Model/Datasource/Database/Sqlite.php

@@ -323,7 +323,7 @@ public function resultSet($results) {
 				$j++;
 				continue;
 			}
-			if (preg_match('/\bAS\s+(.*)/i', $selects[$j], $matches)) {
+			if (preg_match('/\bAS(?!.*\bAS\b)\s+(.*)/i', $selects[$j], $matches)) {
 				$columnName = trim($matches[1], '"');
 			} else {
 				$columnName = trim(str_replace('"', '', $selects[$j]));