请指点，简单的数据库语句$query = "select orderid from orders where customerid = $customerid and amount > ".$_SESSION['total_price']."-.001 and //这句是什么意思？ ."-.001 是什么意思？
amount 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 = '$ship_country'";------解决方案---------------------0.001+0.001------解决方案--------------------total_price 取值上下浮动 0.001饭碗内例如total_price = 1.001取值 1.000 到 1.002------解决方案--------------------就是算术运算的-0.001 与 +0.001例如$_SESSION['total_price'] 的值是 1那么语句就相当于$query = "select orderid from orders where customerid = $customerid and amount >0.999 andamountdate = '$date' andorder_status = 'PARTIAL' andship_name = '$ship_name' andship_address = '$ship_address' andship_city = '$ship_city' andship_state = '$ship_state' andship_zip = '$ship_zip' andship_country = '$ship_country'";