Question

我在PHP的MySqli中遇到订购问题。它是bind_param不能工作的原因还是其他原因。我不确定在这里忘记什么，只是不想接受我的约束。预先感谢。

 @ $db = new mysqli('localhost', 'root', '', 'books');
    // if mysqli_connect_errno() is set, we did not successfully connect. Here we deal with the error.
    if (mysqli_connect_errno()) {
        echo 'Error: Could not connect to database.  Please try again later.</body></html>';
        die();
    }
    $sortOrder = 'title';

    $query = "SELECT ISBN, Author, Title, Price FROM books ORDER BY ?";
    $stmt = $db->prepare($query);
    $stmt->bind_param('s', $sortOrder);

    $stmt->execute();
    $stmt->store_result();
    $stmt->bind_result($isbn, $author, $title, $price);

    echo "<p>Number of books found: " . $stmt->num_rows . "</p>";

    $counter = 0;
    if ($stmt->num_rows > 0) {
        while ($stmt->fetch()) {
            $newBook = new book($isbn, $author, $title, $price);
            $bookList[$counter] = $newBook;
            $counter++;
        }
    } else {
        //Nothing
    }
    $stmt->free_result();
    $db->close();

Answer 1

您不能绑定标识符（表/列），只能绑定值。使用白名单检查值是已知对中的一个，然后将其传递。

if(in_array($column, array('title', 'possible_other_column'))) {
     $query = "SELECT ISBN, Author, Title, Price FROM books ORDER BY $column";
     $stmt = $db->prepare($query);
     $stmt->execute();
} else {
     echo 'Column is not a valid name please select a valid column';
     //or whatever behavior you want to happen, maybe just use a default column

似乎没有为MySqli Php“排序”

1 个答案: