1+1 php counter inside the update_post_meta

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If you’re trying to update the number stored in the meta table, you need to load that value and increment it.

$count = get_post_meta( $bid_id, 'draftnumber', true );
if ( ! $count ) {
    $count = 0;  // if the meta value isn't set, use 0 as a default
                 // We'll be incrementing this right away so it'll be 1
}
$count++;
update_post_meta( $bid_id, 'draftnumber', $count );

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