mysql - 如何在我的 Codeigniter 模型中使用 SQL LEFT JOIN

Question

我在 Codeigniter 模型中使用 LEFT JOIN 进行查询。当我添加 LEFT JOIN 时，我的网页无法正常工作，如下所示

The localhost page isn’t working

localhost is currently unable to handle this request. HTTP ERROR 500

这是我的查询。我添加了 LEFT JOIN(未工作阶段)。我做错了什么？请指导我。我是菜鸟。

$sql = "
        SELECT eu.user_id as user_id, DATE_FORMAT(eu.interview_plan_date, '%Y-%m-%d') as plan_date, DATE_FORMAT(eu.interview_plan_date, '%H:%i:%s') as start_time, DATE_FORMAT(DATE_ADD(eu.interview_plan_date, INTERVAL 1 HOUR), '%H:%i:%s') as end_time, count(1) AS cnt  
        FROM `entry_user_tbl` eu
        LEFT JOIN m_admin ma
        ON ma.admin_id = eu.interview_plan_staff
        WHERE delete_flg = 0 
        AND interview_plan_date LIKE '$year-$month%'
        AND CASE 
                WHEN (SELECT admin_flg FROM m_admin WHERE admin_id = {$login_id} AND delete_flg=0) = 0 THEN eu.interview_plan_staff = {$login_id} 
                WHEN {$id} <> 0 THEN eu.interview_plan_staff = {$id}
                ELSE TRUE 
            END
        GROUP BY DATE_FORMAT(interview_plan_date, '%Y%m%d')
        ";

Answer 1

如果是数据库错误，您可能首先打开显示错误，在 Codeigniter 中，您可以通过编辑 index.php 页面并将环境更改为开发来实现

 define('ENVIRONMENT', 'development');