Can't execute query

MySQL Error: Query was empty

Array
(
    [0] => Array
        (
            [file] => /var/www/vhosts/garsanjoyeros.com/httpdocs/visita/detalleProducto.php
            [line] => 55
            [function] => db_query
            [args] => Array
                (
                    [0] => 
                )

        )

    [1] => Array
        (
            [file] => /var/www/vhosts/garsanjoyeros.com/httpdocs/index.php
            [line] => 447
            [function] => detalleProducto
            [args] => Array
                (
                )

        )

)

This script cannot continue, terminating.