Select column name dynamically mySQL Query

Question

$country="USA";
$dr=$wpdb->get_results("SELECT $country FROM wp_shipping WHERE ID=$ids");

I want the above query in WordPress file, where country name is given dynamically but I am not getting how to do this. When I execute the above query, the result is nothing.

Answer 1

I guess one could argue that this is somewhat wordpress related, because you are trying to get_results() from $wpdb, but like @MarkKaplun said your problem is that you are using the SQL wrong. Below code is an example on how to do it correct:

$dr = $wpdb->get_results(
    $wpdb->prepare(
        "SELECT * FROM wp_shipping WHERE country = %s AND ID = %d",
        $country, $ids
    )
);

This is an example, you might have to fit it to your needs. For additional information you should take a closer look at the codex Class Reference: wpdb.