$wpdb:insert, more arguements in $format array than in $data

Question

I'm making some customizations for a website, and I cam across this piece of code of a theme:

        $wpdb->insert(
            $table_name,
            array(
                'user_id'              => $user_id,
                'search_wp_query_args' => $search_args,
                'search_query_str'     => $search_url,
                'time'                 => current_time( 'mysql' ),
            ),
            array(
                '%d',
                '%s',
                '%s',
                '%s',
                '%s',
            )
        );

What's the reason for having one more element in the $format array than in the $data array? In the docs it implies that those should have the same number of elements, for a 1-on-1 matching... Does it account for the primary key of the table, which isn't in the $data array anyway though? Is this a bug or there is an explanation behind it?

Answer 1

I think you're assuming this is intentional, it's probably just a bug in the theme, what it's stating is the 5th parameter is a string, but there is no 5th parameter so it's ignored.

The most likely reason is that during development a 5th entry was removed and the author forgot to update the second array, or that they accidentally duplicated a line