get_post_custom 将返回给定帖子的所有meta\\u键=>meta\\u值对。然而，它以一种奇怪的格式返回字段。

例如：。

<?php
$meta = get_post_custom(1);

/*
$meta would be...

arrary(
   \'some_meta_key\' => array(
       \'one_meta_value\'
   )
);
*/

<?php
function wpse65225_get_all_meta($type)
{
    global $wpdb;

    $res = $wpdb->get_results($wpdb->prepare(
        "SELECT post_id, meta_key, meta_value FROM {$wpdb->postmeta} WHERE post_id IN
        (SELECT ID FROM {$wpdb->posts} WHERE post_type = %s)", $type
    ), ARRAY_A);

    return $res;
}