Edit %functions.php% to create the update under #3 Things to keep in mind: Where do you want to store the values? Where are you storing the check-ins? How often do we update? How do we need to query the data in the future?

Expected, something like: foreach( $values as $key => $value ) { @$values[$key] = (string) $value; if ( $values[$key] === '?' || $values[$key] === '' || $values[$key] === 'Array' ) { continue; } if ( array_key_exists( $key, $this->tags ) ) { if ( $values[$key] != $this->tags[$key] ) { $updates["possible.$key"] = array( $values[$key], 0 ); } } else { $updates["possible.$key"] = array( $values[$key], 0 ); } } $update = array( '$addToSet' => $updates ); $this->d->poi->update( array( '_id' => $this->o['_id'] ), $update );