更新金额＆lt; = 0设置信用额的用户

Question

$check_empty_user = $DBcon->query("SELECT * FROM bubble_spends where a_amount <= 0");
$count=$check_empty_user->num_rows;
$username23=$DBcon->query("SELECT a_name FROM bubble_spends where a_amount <= 0 LIMIT 1");

$count2=$username23->fetch_array;

 if (!$count==0) {

  $DBcon->query("DELETE FROM bubble_spends where a_amount <= 0");
  $DBcon->query("UPDATE users SET credits = credits+100000 WHERE username='$count2'");
        echo "user has been outspended";
    }

主要目标是通过它来实现，当bubble_spend的数量小于0时，它应该从冒泡花费中选择a_name，然后更新用户set credits = credits + 10 where username = $ a_name

但这不起作用，我忙于这个2个小时，我无法得到修复

Answer 1

您正在尝试在bubble_spends表中获取数量少于0的所有用户，然后从该表执行删除并在另一个表上进行更新。

要以简单的方式执行此操作，请从bubble_spends表中获取所有小于0的名称，然后使用IN运算符和内部查询来更新它们。更新后，您最好从其他表中删除它们。

$DBcon->query("UPDATE users SET credits = credits+100000 
WHERE username IN (SELECT a_name FROM bubble_spends where a_amount <= 0)");

$DBcon->query("DELETE FROM bubble_spends where a_amount <= 0");

这应该这样做。