将meta键添加到所有帖子-自定义帖子类型

Question

I actually wrote this function a week ago, but I didn't save it and am having trouble figuring it out again.

Here is a different function I wrote that adds the meta key 'orientation' with respective values depending on image size. I'd like to convert this to a function that I can insert in my functions.php and run once to add the field to all existing posts, then delete it after.

I've tried a number of different methods. Any and all help would be greatly appreciated.

add_action( 'save_post_portfolio', 'add_orientation' );
function add_orientation($post_ID) {
    global $wpdb;

            $post_thumbnail_id = get_post_thumbnail_id( $post->ID );
            $orientation = get_post_meta($post->ID, 'orientation', TRUE);
            if($orientation != '') {
            }
            elseif($post_thumbnail_id) {
            $image = wp_get_attachment_image_src( $post_thumbnail_id, 'full' );
            if($image[1] >= 0 && $image[2] >= 650) {
            add_post_meta($post_ID, 'orientation', 'portrait');
            }
            elseif($image[1] >= 0 && $image[2] <= 650) {
            add_post_meta($post_ID, 'orientation', 'landscape');
            }
        }   

}

Answer 1

I'm not sure, but should work. Try this: Main function:

function get_post_meta_data($post_id){
global $wpdb;
$wpdb->query("SELECT 'post_id','meta_key','meta_value' FROM $wpdb->postmeta WHERE 'post_id' = $post_id");
foreach($wpdb->last_result as $k => $v){
    //data:
    //$v->meta_key == meta_key of post 
    //$v->meta_value == meta_value of post
    //$post_id == post id
    /*
    Do here what you want
    */
};
}

and once-launch function:

function update_meta_orientation()
{
global $wpdb;
//get all post id:
$wpdb->query("SELECT 'post_id' FROM $wpdb->postmeta");
//call function for each post
foreach($wpdb->last_result as $key => $value)
    {
    get_post_meta_data($value->post_id);
    }
}

Answer 2

Wasn't sure how Sysanin code related to my answer, but I wrote a solution that finally worked

$args = array( 'numberposts' => -1, 'post_type' => 'portfolio' );
$postslist = get_posts( $args );
foreach ($postslist as $post) :  setup_postdata($post);
            $post_id = get_the_ID();
            $post_thumbnail_id = get_post_thumbnail_id( $post_id );
            $orientation = get_post_meta($post_id, 'orientation', TRUE);
            if($orientation =='') {
            if($post_thumbnail_id) {
            $image = wp_get_attachment_image_src( $post_thumbnail_id, 'full' );
            if($image[1] >= 0 && $image[2] >= 650) {
            add_post_meta($post_id, 'orientation', 'portrait');
            }
            elseif($image[1] >= 0 && $image[2] <= 650) {
            add_post_meta($post_id, 'orientation', 'landscape');
            }
        }   
    }
    else {
    }
endforeach;

and then here it is stripped for anyone's use

$args = array( 'numberposts' => -1, 'post_type' => 'cpt' );
$postslist = get_posts( $args );
foreach ($postslist as $post) :  setup_postdata($post);
$post_id = get_the_ID(); // use this variable
// do stuff here          
endforeach;