Update all posts at once

Question

I have added a custom taxonomy to my posts, that will get a value by iteself on post_update action. What will be the SQL query to update all my posts at once so that the taxonomy value is added to each of them. Also will updating from SQL call the update_post action of wordpress?

Answer 1

I got the same need, personally I used wp_set_object_terms after a WP_Query resquest on all of my custom post type. I suppose you could replace my_custom_type with post in the following quote of my code:

$my_query = array(
    'post_type' => array( 'post', 'my_custom_type' ) );
$the_query = new WP_Query( $my_query );

while ( $the_query->have_posts() ) : $the_query->the_post();

    $id = get_the_ID();
    wp_set_object_terms( $id, "my_new_tag_value", "my_tax_slug", $append=true );

endwhile;

Answer 2

I would not do this with SQL. I would do this with WP_Query. You can use WP_Query to get all desired posts...which in this case is all posts. Then you can loop through the posts and use wp_set_object_terms() to set the desired category (or categories) on each post.