javascript - 即使数据库连接已定义，Ajax 调用也会返回 Class 'db' not found 错误

Question

我想使用 ajax 更新我的内容。只需选择下拉值，内容就会根据所选的下拉值填充新值。但是每次我从下拉列表中选择一个值时，它都会返回一个 Class 'db' not found 错误，并且我已经放在 required_once 上的其他函数似乎也不起作用。我已经尝试解决这个问题 2 天了，但仍然无法正常工作。有人可以帮我解决这个问题吗？谢谢。这是我的代码:

请注意，加载 my_file.php 时，会调用 course_overview_functions.php，加载 else 部分并返回适当的值。当执行ajax调用时，如果part返回true，则返回类'db'未找到错误。

my_file.php

require_once 'includes/course_overview_functions.php';  

$course_array = array();
$pid_shown = array();
$course_array = ajax_request_val();

my_file.php(javascript部分)

$(':input').change(function(event){
    event.preventDefault();
        $('.minimal_table').html('<img src="../images/loading_trans.gif"  style="position:relative; margin:350px; margin-top:250px;" />');
        alert($(this).val());

       var val_id = $(this).val();

       var postData = {val_id:val_id, ajax:1 };

$.ajax({
  url: "../includes/course_overview_functions.php",
  async: false,
  type: "POST",
  data: postData,
  dataType: "html",
  success: function(data){
    setTimeout(function(){
    $('.minimal_table').html(data);
    },2000);
     console.log(data);
  },
  });

 });

course_overview_functions.php

function ajax_request_val(){


$val_id = $_POST['val_id'];
$field = "course_type";

if(isset($val_id)){


  $plans = db::getTable('plan',$field,$val_id);
            foreach ($plans as $plan) {
                if (eventAccessLevel(null, $plan['plan_id']) != EVENT_ACCESS_NONE) {
                    $course_array[] = getCourseDetails(null, $plan['plan_id']);
                    $pid_shown[] = $plan['plan_id'];
                }
            }
            $events = db::getTable('tbl_event',$field,$val_id);
            foreach ($events as $event) {
                if (!in_array($event['plan_id'], $pid_shown)) {
                    $event_id = $event['event_id'];
                    if (eventAccessLevel($event_id, null) != EVENT_ACCESS_NONE) {
                        $course_array[] = getCourseDetails($event_id, null);
                    }
                }
            }

            return $course_array;
}

else{

            $plans = db::getTable('plan');
            foreach ($plans as $plan) {
                if (eventAccessLevel(null, $plan['plan_id']) != EVENT_ACCESS_NONE) {
                    $course_array[] = getCourseDetails(null, $plan['plan_id']);
                    $pid_shown[] = $plan['plan_id'];
                }
            }
            $events = db::getTable('tbl_event');
            foreach ($events as $event) {
                if (!in_array($event['plan_id'], $pid_shown)) {
                    $event_id = $event['event_id'];
                    if (eventAccessLevel($event_id, null) != EVENT_ACCESS_NONE) {
                        $course_array[] = getCourseDetails($event_id, null);
                    }
                }
            }

            return $course_array;
   }    
  }

数据库连接.php

public static function getTable($tableName,$field='',$type_id='') {
        if (!self::$db) self::connect();

        if(!empty($type_id)){
            $tableName = self::$db->escape_string($tableName);
            return self::getObjects('SELECT * FROM `' . $tableName . '` WHERE `'. $field .'` = `'. $type_id .'`;');
        }
        else{
            $tableName = self::$db->escape_string($tableName);
            return self::getObjects('SELECT * FROM `' . $tableName . '`;');
        }
    }

错误:

Fatal error: Class 'db' not found in /home/cm/public_html/includes/course_overview_functions.php on line 207

Answer 1

你的数据库连接...你有一个函数，但没有定义类。您需要定义一个class db。