How to add a custom field to all posts in Wordpress?

Question

PHP

Good evening, tell me how to add a custom field in wordpress to all posts? Maybe via functions?

Answer 1

select all records:
then in a loop, or insert a field with mysql queries, or add_post_meta
I don’t see any other options

Answer 2

I use the More Fields plugin

Answer 3

Code: Custom field
Plugin: Advanced Custom Field
If you have any questions, ask - I'll try to help.
PS Displaying custom fields in the admin panel for each entry can be done through the "screen settings". Check the box, and at the bottom when creating records, there will always be a column of arbitrary fields.