Custom post type – Loop out in random order but same 15 to appear first… still random

Question

1 – I’d create a custom field for marking a post as ‘favourite’.

2- Then you would add a meta_query bit to the code in which you are querying the DB.

There are several ways to do (1) and several ways to do part (2).

How familiar are you with WordPress development?

If your theme isn’t being built on a framework, then the quickest way to do point (1) will probably be to use at Advanced Custom Fields Plugin.

Read the docs on their website, to create a custom field.

For this task, a checkbox type field will be relevant.

Then, on the website, you’ll need to search for posts that have that custom field be whatever value indicates that is a ‘favourite’ (with a checkbox, the value would be 1).

There several ways, depending on how you’re doing things:

(1) – WP_Query

(2) – pre_get_posts filter

(3) get_posts() function

…. several other methods.

Here’s how you can do it using WP_Query, assuming your custom field is called 'is_favourite':

$args = array(
    'meta_query' => array(
        array(
            'key' => 'is_favourite',
            'value' => 1
        )
    ),
'orderby' => 'meta_value_num rand',
'posts_per_page'=>-1
);

$the_query = new WP_Query( $args );

For a full explanation of how to use WP_Query – https://codex.wordpress.org/Class_Reference/WP_Query