Php Foreach循环和阵列构建

我有一个管理区，在那里他们可以一次删除多个用户。这是处理删除的代码的一部分。基本上，它会遍历用户ID并删除每个标记为选中的ID

if ($_POST['doDelete'] == 'Delete') {
    if (!empty($_POST['u'])) {
        foreach ($_POST['u'] as $uid) {
            $id = escape($uid);
            $delete = Nemesis::query("DELETE FROM users WHERE id = '{$id}' AND id <> '{$_SESSION[user_id]}'");
            if (!$delete) {
                $msg->add('e', QUERY_ERROR);
                redirect('users.php');
                exit();
            }
        }
    }
    /* we need a way to iterate over users deleted */
    $msg = new Messages();
    $msg->add('s', QUERY_DELETE_SUCCESS);
    redirect('users.php');
    exit();
}

function get_user_name_from_id($user_id)
{
    if ($_SESSION['user_level'] == ADMIN_LEVEL) {
        $viewUserMod = 1;
    } else {
        $config = Nemesis::select("usr_view_cm", "config");
        $row_config = $config->fetch_assoc();
        $viewUserMod = $row_config['usr_view_cm'];
    }
    if (is_numeric($user_id) && $viewUserMod == 1) {
        $sql = Nemesis::select("full_name", "users", "id = {$user_id}");
        if ($sql->num_rows > 0) {
            $user_name = $sql->fetch_assoc();
            return $user_name['full_name'];
        } else {
            // user name cannot be matched with db, either error, or most likely user was deleted
            return 'User ' . $user_id;
        }
    } else {
        return $user_id;
    }
}

---

其中显示QUERY\u DELETE\u SUCCESS，我想输出类似Deleted Bob、Jack、Tim等的内容。我有一个函数，它使用用户id并获取他们的姓名。问题是一旦迭代完成。显然，数据库中不再存在这些用户，我无法获取他们的姓名。是否有方法在循环期间运行此函数，并构建字符串或数组。可以输出以代替消息？

在UID上循环时，您可以将名称添加到数组中，如下所示：

$names = array();
if (!empty($_POST['u'])) {
    foreach ($_POST['u'] as $uid) {
        $names[] = get_user_name_from_id($uid);
        $id = escape($uid);
        $delete = Nemesis::query("DELETE FROM users WHERE id = '{$id}' AND id <> '{$_SESSION[user_id]}'");
        if (!$delete) {
            $msg->add('e', QUERY_ERROR);
            redirect('users.php');
            exit();
        }
    }
}

$names = implode(', ',$names);
$message = "Deleted $names";

---

您应该能够做到这一点：

if ($_POST['doDelete'] == 'Delete') {
    $deleted = array();
    if (!empty($_POST['u'])) {
        foreach ($_POST['u'] as $uid) {
            $id = escape($uid);
            $username = get_user_name_from_id($uid);
            $delete = Nemesis::query("DELETE FROM users WHERE id = '{$id}' AND id <> '{$_SESSION[user_id]}'");
            if (!$delete) {
                $msg->add('e', QUERY_ERROR);
                redirect('users.php');
                exit();
            }
            $deleted[] = $username // push name to array after deletion is successful
        }
    }
    /* The $deleted array now holds the names of the deleted users.
     * Do with it what you want.
     */
    $names = implode(",", $deleted)
    $msg = new Messages();
    $msg->add('s', QUERY_DELETE_SUCCESS . " Deleted: $names");
    redirect('users.php');
    exit();
}

这里可以做一些改进，包括将许多小的单个查询有效地组合成几个大的查询，错误处理不会在第一个错误时重定向，而是在所有处理完成后重定向到包含成功和错误列表的页面，但这是基本思想

下面是一个快速更改，它将执行所有操作，即使其中一个操作出错：

if ($_POST['doDelete'] == 'Delete') {
    $deleted = array();
    $errored = array();
    if (!empty($_POST['u'])) {
        foreach ($_POST['u'] as $uid) {
            $id = escape($uid);
            $username = get_user_name_from_id($uid);
            $delete = Nemesis::query("DELETE FROM users WHERE id = '{$id}' AND id <> '{$_SESSION[user_id]}'");
            if (!$delete) {
                $errored[] = $username;
            } else {
                $deleted[] = $username // push name to array after deletion is successful
            }
        }
    }
    /* The $deleted array now holds the names of the deleted users.
     * The $errored array now holds the names of users who were not deleted due to errors.
     * Do with them what you want.
     */
    $msg = new Messages();
    $names_deleted = implode(",", $deleted)
    $msg->add('s', QUERY_DELETE_SUCCESS . " Deleted: $names_deleted");
    if (count($errored) > 0) {
        $names_errored = implode(",", $errored)
        $msg->add('e', QUERY_ERROR . " Did not delete: $names_errored");
    }
    redirect('users.php');
    exit();
}

---

这意味着您必须调用getname函数，并使用它在执行每个delete语句之前构建一个已删除用户名的数组。例如，如果我们有3次删除。第一个有效，第二个无效，第三个也有效。你怎么知道哪个成功了，哪个失败了？我想我明白了。所以基本上，如果它失败了，就做一个数组，如果它通过了，就做另一个数组。最后检查它们是否都是空的。如果它们都是arnt，则显示已删除和未删除的用户？@Alex是的，这与我的做法很接近。我已经更新了我的例子。是的，这和我写的差不多。除了我用过的如果！空$fail。。。对数组进行计数和清空有什么区别吗？因为我读到他们实现了同样的目标。@Alex是的，数一数$array>0和！空$array将执行相同的操作：检查数组是否有任何元素。使用哪一种主要取决于个人偏好。