PHP/MYSQL Loop 只迭代一次，无法将数据存储到数组中

Question

我有以下一段代码，它连接两个表，然后返回 users 表中的所有教师用户。

有资格成为教师的用户，然后从teachers 表中检索信息

所以假设 users 表中有 3 个用户符合教师资格，所有这 3 个用户都应该存储在一个数组中。

页面加载时数组变空

SQL语句

//IF my reasoning is correct the folllowing sql query should select alll users who qualifies as teachers
$sql = "SELECT users.*, teachers.*
        FROM users INNER JOIN teachers ON teachers.userID = users.userID";

功能

public function showAllTeachers()
    {
        $db = DB::getInstance();
        $sql = "SELECT users.*, teachers.*
        FROM users INNER JOIN teachers ON teachers.userID = users.userID";

        //simple DB QUERY
        $stmnt = $db->prepare($sql);
        $stmnt->execute();
        $teachers = $stmnt->fetchAll();
        $teacherInfo = array();

        //Check if there are any users who qualifies as teachers else return fals
        if ($stmnt->rowCount() > 0) {
            foreach($teachers as $teacher){
          //Store all teacher info in array $teacherInfo
          //There are more than 1 teacher so loop shouldl iterate more than once

                $teacherInfo = array('name' =>$teacher['firstname'], 'headline' =>$teacher['headline'], 'location' => $teacher['location'],
                    'age' => $teacher['age'], 'experience' => $teacher['experience'], 'imgPath' => $teacher['imgPath']);
            }//foreach

            //return array with teacher info
            return $teacherInfo;
        }//rowcount
        else {
            return false; //no teachers
                }
    }//function

因为有超过 1 个用户有资格成为教师 $teacherInfo 现在应该包含所有这些教师的数据

清空数组

以下内容在页面加载时运行，应该会显示所有教师。

我的问题当清空数组 $allTeachers 时，我只得到一个结果(老师)。因此我的循环出于某种原因只迭代一次

 $teachers = new TeacherSearch();
           $allTeachers = $teachers->showAllTeachers();
            if(is_array($allTeachers)){
                foreach($allTeachers as $key => $teacher){
                    echo $key;
                    echo $teacher;
                    echo '<br />';
                }
              }

非常感谢任何帮助

附加信息

数据库

教师表

用户表

用户表数据

Answer 1

好像不是你的循环只执行一次的问题，在里面加上echo 'test'，你会看到它执行了多次(只要$teachers 当然有不止一个元素。

问题是您在每个 foreach 循环执行时覆盖了 $teacherInfo，而不是向其附加一个新数组。

替换:

$teacherInfo = array('name' =>$teacher['firstname'], 'headline' =>$teacher['headline'], 'location' => $teacher['location'],
    'age' => $teacher['age'], 'experience' => $teacher['experience'], 'imgPath' => $teacher['imgPath']);

与:

$teacherInfo[] = array('name' =>$teacher['firstname'], 'headline' =>$teacher['headline'], 'location' => $teacher['location'],
    'age' => $teacher['age'], 'experience' => $teacher['experience'], 'imgPath' => $teacher['imgPath']);