Question

我有以下“课程”课程：

class Course {
    // The constructor just sets the database object
    public function __construct($mysqli) {
        $this->mysqli = $mysqli;
    }
    public function getCourseInfoByID($id) {
        $result = $this->mysqli->query("SELECT * FROM courses WHERE id='$id'");
        $course_info = $result->fetch_array();

        // If found, return the student object
        if($course_info) {
            return $course_info;
        } 
        return FALSE;
    }
}

当我声明该类并尝试运行函数“getCourseInfoByID”时，我得到了奇怪的结果（见下文）

$cid = process_get_request('cid');
$course = new Course($mysqli);

if(! $course_info = $course->getCourseInfoByID($cid)) {
    $error[] = "Invalid Course ID";
    setError();
    redirectTo("instructors.php");
}
print_r($course_info);

我明白了：

Array ( [0] => 2 [id] => 2 [1] => 1 [course_type_id] => 1 [2] => 1 [instructor_id] => 1 [3] =>  Tooele [dz_name] =>  Tooele [4] => 4 Airport Road [dz_address] => 4 Airport Road [5] => Tooele [dz_city] => Tooele [6] => Utah [dz_state] => Utah [7] => 84020 [dz_zip] => 84020 [8] => [dz_email] => [9] => 2011-12-30 17:25:12 [created] => 2011-12-30 17:25:12 [10] => 2012-01-02 16:24:08 [start_date] => 2012-01-02 16:24:08 [11] => 2012-01-08 16:24:17 [end_date] => 2012-01-08 16:24:17 [12] => 10 [student_slots] => 10 [13] => Brett  will also be assisting in teaching this course as Nathan's assistant. Brett paid Nathan quite well to be his assistant. [notes] => Brett will also be assisting in teaching this course as Nathan's assistant. Brett paid Nathan quite well to be his assistant. [14] => 0 [approved_by] => 0 [15] => 0000-00-00 00:00:00 [approved_on] => 0000-00-00 00:00:00 [16] => 0 [completed] => 0 )

为什么每条记录都重复？

Answer 1

这种情况正在发生，因为您正在返回数字和关联索引。您应该使用fetch_assoc()或传递相应的常量MYSQLI_ASSOC或MYSQLI_NUM来返回这些键。

请参阅mysqli_result::fetch_array()上的文档。

顺便说一下，我会输入提示你的构造函数来强制传递mysqli类，这样你就不会意外地传递一个无效的参数。

Answer 2

读取the docs以获取fetch_array（）方法。第二个参数默认为MYSQLI_BOTH。

PHP OOP：奇怪的数组返回

2 个答案: