就是算术运算的-0.001 与 +0.001例如$_SESSION['total_price'] 的值是 1那么语句就相当于$query = "select orderid from orders where customerid = $customerid and amount >0.999 and amount < 1.001 and date = '$date' and order_status = 'PARTIAL' and ship_name = '$ship_name' and ship_address = '$ship_address' and ship_city = '$ship_city' and ship_state = '$ship_state' and ship_zip = '$ship_zip' and ship_country = '$ship_country'";
customerid = $customerid and
amount >0.999 and
amount < 1.001 and
date = '$date' and
order_status = 'PARTIAL' and
ship_name = '$ship_name' and
ship_address = '$ship_address' and
ship_city = '$ship_city' and
ship_state = '$ship_state' and
ship_zip = '$ship_zip' and
ship_country = '$ship_country'";