I have a question: I have events website with testdata. Events, locations and artist. All three have custom fields filled and there are relations using MB relations: Events to Locations and Events to Artist.
When I copy the website from staging to live I will remove all the testdata. What is the correct way so that the custom fields in the database also removed and the relationtable is cleaned?
Meta Box and WordPress do not have an official option to delete the field value (post meta). You can create a custom loop and delete post meta with the function delete_post_meta() or use a third-party plugin to do that https://wordpress.org/plugins/wp-bulk-delete/
For the custom table mb_relationships, you can access your database and delete all rows in the table.
I'm not sure how you deleted the field value, but if that query returns no results, the row (meta ID) is deleted. Or you can go to the database and see the result.
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