The code you’ve linked to above:
//$sql set to raw SQL statement
$sql = $wpdb->prepare($sql,$feed_id);
if($wpdb->query($sql)){
$resp->uf_error = $wpdb->print_error();
}
So if there isn’t, an error you try displaying the ‘error’ with $wpdb->print_error()
. Also$wpdb->print_error()
doesn’t return an error, it prints it.
It’s (probably) the printing of that non-error that is causing an error in your second database query, the one for which an error is logged.
Side note: take a look at the wpdb
class. There are methods in there that handle INSERT/UPDATE queries so you don’t have to do them manually.