Can't execute query

select * from imagenesProductos where idProducto=

MySQL Error: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1

Array
(
    [0] => Array
        (
            [file] => /home/xxpawewf/public_html/culdesaconline.es/visita/detalleProducto.php
            [line] => 103
            [function] => db_query
            [args] => Array
                (
                    [0] => select * from imagenesProductos where idProducto=
                )

        )

    [1] => Array
        (
            [file] => /home/xxpawewf/public_html/culdesaconline.es/index.php
            [line] => 585
            [function] => detalleProducto
            [args] => Array
                (
                )

        )

)

This script cannot continue, terminating.