Let me preface this by saying that while I am a software engineer, I’m just getting my feet wet in WordPress development.
My site has two uses of ACF for board games.
1) Writers can select a single board game which creates a record in wp_postmeta with a meta_key of board_game and a meta_value of a single related post_id.
2) I _want_ writers to be able to select multiple board games. I just added that feature this morning and it writes a record to wp_postmeta with a meta_key of board_games and a meta_value of a JSON blob. As you can see from the image below both records are available in a raw SQL query.
https://imgur.com/a/gRiihZD
Is it possible to retrieve all occurrences of a given post_id from two relationships in a single query? Perhaps something like this?
$posts = get_field('board_game', 'board_games');
The goal is that for a given board game, Catan for example, I would be able to retrieve every post on my site which ever mentioned Catan; whether as a single entry or as past of a multi-select box.
First, the value in the DB is not a JSON value, it is a serialized array, but that does not matter.
In order to get all posts with a value, first you need to know the post ID of the value you’re looking for, then using this value you need to do a WP_Query to get the posts.
I’m only including the meta_query portion of the query args
'meta_query' => array(
'relation' => 'OR',
array(
'key' => 'board_game',
'value' => $post_id
'compare' => '='
),
array(
'key' => 'board_games',
'value' => '"'.$post_id.'"',
'compare' => 'LIKE'
)
)
see https://developer.wordpress.org/reference/classes/wp_query/, https://www.google.com/search?client=firefox-b-1-d&q=acf+query+by+custom+field and https://www.advancedcustomfields.com/resources/querying-relationship-fields/
John, thanks for taking the time to respond. Let me answer some of your questions, and ask a few of my own.
1) There’s already a page on my site for this, but I’m looking to add functionality to it: https://www.meeplemountain.com/boardgame/no-thanks/
2) $post->ID is already available on the page.
I’ll take a look at the code examples you linked to and see if I can hash it out. Thank you.
Let me know if you have any questions. I could probably have explained everything but it would have been a very long explanation where everything is already written.
