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HomeBackend DevelopmentPHP TutorialMysql 数据库问题,该语句是什么意思

$query = "select orderid from orders where                 customerid = $customerid and                 amount > ".$_SESSION['total_price']."-.001 and //这句是什么意思?                amount < ".$_SESSION['total_price']."+.001 and  //这句是什么意思?                date = '$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'"; 


回复讨论(解决方案)

total_price 取值上下浮动0.001

在PHP中断点调试看一下 $query 的实际内容就明白了。

在PHP中断点调试看一下 $query 的实际内容就明白了。


如何断点调试,我只知道C/C++等可以调试,PHP也可以吗??请指点。而且这个什么是上下浮动啊,还是不懂啊
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