Fix DO regen task query conditions (#1643)

Add conditions for the regen task SQL query to whereClauses to ensure
that they end up after the keyword WHERE instead of manually appending
them to the query.

lib/task/digitalobject/digitalObjectRegenDerivativesTask.class.php

@@ -191,22 +191,20 @@ protected function execute($arguments = [], $options = [])
 
         // Only regenerate derivatives for remote digital objects
         if ($options['only-externals']) {
-            $query .= ' AND do.usage_id = '.QubitTerm::EXTERNAL_URI_ID;
+            array_push($whereClauses, sprintf('do.usage_id = %d', QubitTerm::EXTERNAL_URI_ID));
         }
 
         // Only regenerate derivatives for digital objects of specific media type
         if ($options['media-type']) {
-            $query .= ' AND do.media_type_id = '.$validMediaTypes[$options['media-type']];
+            array_push($whereClauses, sprintf('do.media_type_id = %d', $validMediaTypes[$options['media-type']]));
         }
 
         // Limit ids for regeneration by json list
         if ($options['json']) {
             $ids = json_decode(file_get_contents($options['json']));
-            $query .= ' AND do.id IN ('.implode(', ', $ids).')';
+            array_push($whereClauses, 'do.id IN ('.implode(', ', $ids).')');
         }
 
-        $query .= ' AND do.usage_id != '.QubitTerm::OFFLINE_ID;
-
         if ($options['no-overwrite']) {
             $query .= ' LEFT JOIN digital_object child ON do.id = child.parent_id';
             array_push($whereClauses, 'do.parent_id IS NULL AND child.id IS NULL');
@@ -242,6 +240,8 @@ protected function execute($arguments = [], $options = [])
             $query .= sprintf(' WHERE %s', implode(' AND ', $whereClauses));
         }
 
+        $query .= ' AND do.usage_id != '.QubitTerm::OFFLINE_ID;
+
         // Do work
         foreach (QubitPdo::fetchAll($query) as $item) {
             $do = QubitDigitalObject::getById($item->id);