get_post() is not returning correct value

Question

I have a post and i need to update its post_parent. So i have used below code to update the post_parent value. Old post_parent is 844 and using query i have updated the value to 370 using below:

    global $wpdb;
    $table_name = $wpdb->prefix . "posts";
    $add_plan_to_team = $wpdb->update( $table_name, array( 'post_parent' => '370' ), array('ID'=> '84887'));
    // UPDATE wp_posts SET post_parent=370 WHERE ID=84887 

In next line , i need to get the post and then perform some functions. I am doing it like this

     $post = get_post( 84887 );

But instead of returning updated values, i am getting the old post_parent value in return. Like below

WP_Post Object
(
    [ID] => 84887
    [post_author] => 2
    [post_date] => 2020-02-27 10:55:11
    [post_date_gmt] => 2020-02-27 10:55:11
    [post_content] => 
    [post_title] => MyTeam
    [post_excerpt] => 
    [post_status] => publish
    [comment_status] => closed
    [ping_status] => closed
    [post_password] => 
    [post_name] => allus-cu
    [to_ping] => 
    [pinged] => 
    [post_modified] => 2020-08-24 19:03:02
    [post_modified_gmt] => 2020-08-24 19:03:02
    [post_content_filtered] => 
    [post_parent] => 844   // This value is not correct. This should be 370
    [guid] => https://train.localdev.com/?post_type=wc_memberships_team&p=84887
    [menu_order] => 0
    [post_type] => wc_memberships_team
    [post_mime_type] => 
    [comment_count] => 0
    [filter] => db
)

I have checked in Database and in database, post_parent value is updated one.

Complete Code in all together:

global $wpdb;
$table_name = $wpdb->prefix . "posts";
$add_plan_to_team = $wpdb->update( $table_name, array( 'post_parent' => '370' ), array('ID'=> '84887'));

if($add_plan_to_team){
    $post = get_post( $team_id, 'OBJECT', 'db' );
    echo '<h1> team_updated </h1>';
    print_r($post);            
}

Please tell me how can i fix it.

Answer 1

That's not how you update posts. Because you used raw SQL to do it, none of the filters or actions fired, and none of WP_Cache was updated, so it'll return an old version of the post it fetched earlier when you call get_post.

Instead, if you want to update a post, use wp_insert_post and pass the posts ID parameter.

E.g.

$result = wp_insert_post( [
    'ID' => 84887,
    'post_parent' => 370,
] );

Additional notes:

• Don't use raw SQL to do things if there's an API ( for this there were several )
• Don't hardcode post IDs, use slugs if you must hardcode anything. All it takes is an accidental post deletion and the code has to be changed at least with slugs you can rename a post and it works again ( and it won't work if you migrate the site with hardcoded numbers )
• numbers aren't strings, use 5 not '5' especially when using SQL functions