I have the following function that works fine. Is there a better way to do it and will this be efficient if I have 100+ rows returned from each table?

The database

Tables

• wcx_articles
• wcx_videos
• wcx_apps
• wcx_links

The corresponding _active column for each table

• article_active
• video_active
• app_active
• link_active

_active is a switch 1 or 0

This is my current function

public function findInactiveItems() {
        
    $query = "SELECT * FROM wcx_articles WHERE article_active = '0'
    UNION
    SELECT * FROM wcx_videos WHERE video_active = '0'
    UNION
    SELECT * FROM wcx_apps WHERE app_active = '0'
    UNION
    SELECT * FROM wcx_links WHERE link_active = '0'
    ";
        if( $this->num_rows( $query ) > 0 ) {    
            $count = $this->num_rows($query);
            return $count;
        }
    }

 public function num_rows( $query ) {
    $query = $this->link->query( $query );
    if( mysqli_error( $this->link ) ) {
        $this->log_db_errors( mysqli_error( $this->link ), $query, 'Fatal' );
        return mysqli_error( $this->link );
    }
    else {
        return mysqli_num_rows( $query );
    }
    mysqli_free_result( $query );
}