WP_Query "OR": Find posts by ID, Name or Post Title?

Question

Hey there for some reason I have a function which has to find posts by either ID, name or post title. It looks like this:

/**
 * @param $name_or_id: Name or ID of the post to find
 * @param $posttype: The Post Type
 * @return null|WP_Post
 */
function r2o_find_post($name_or_id,$posttype) {

    if(is_numeric($name_or_id)) {
        $id = abs(intval($name_or_id));
        if($id > 0) {
            $post = get_post($id);
            if(is_object($post) && $post->post_type == $posttype) {
                return $post;
            }
        }
        return null;
    }

    $slargs = array(
        'post_title'        => $name_or_id,
        'post_type'   => $posttype,
        'post_status' => 'publish',
        'numberposts' => 1
    );
    $pt = get_posts($slargs);

    if(is_array($pt)) {
        return $pt[0];
    }
    return null;
}

However in $slargs I can only do:

post_title => $name_or_id 
OR 
post_name => $name_or_id

Can I do this "OR"-relationship with WP_Query/get_posts without doing two seperate queries?

Answer 1

No. WP_Query class doesn't support OR based conditional query on same table's columns. So in this case you have to write your own SQL query. And as there is a query must to get this single post, it's not gonna hamper the performance. :)

However, I have re-write your code a slightly different way. This way you wouldn't need to use both get_post() and get_posts(). Only one get_posts() call would be enough. Here is this-

/**
 * @param $name_or_id: Name or ID of the post to find
 * @param $posttype: The Post Type
 * @return null|WP_Post
 */
function r2o_find_post( $name_or_id, $posttype ) {

    $slargs = array(
        'post_title'  => $name_or_id,
        'post_type'   => $posttype,
        'post_status' => 'publish',
        'posts_per_page' => 1,
    );

    if( is_numeric( $name_or_id ) ) {
        $id = abs( intval( $name_or_id ) );
        if( $id > 0 ) {
            unset( $slargs[ 'post_title' ] );
            $slargs['post__in'] = [ $name_or_id ];
        }
    }

    $pt = get_posts( $slargs );

    if( is_array($pt) ) {
        return $pt[0];
    }
    return null;
}

My main theory above there is, we are manipulating the arguments of get_posts() based on the type of name_or_id parameter.

Hope this above helps.