php - 加入查询在 Codeigniter 中不起作用

Question

public function getQuestions($params = "",$page= "all", $count=false){
$this->db->query('SELECT  questions.questions_id, questions.question_description,
        questions.question_explanation, questions.created_date,
        questions.updated_date, questions.is_active,
        diffLevels.difficulty_levels_title
    FROM  '.TBL_QUESTION.' as questions
    INNER JOIN  '.TBL_DIFFICULTY_LEVELS.' as diffLevels
           ON questions.fk_difficulty_levels_id = diffLevels.preference
    WHERE  questions.is_active=1');
            $Q = $this->db->get();
            if ($Q->num_rows() > 0) { 
                foreach ($Q->result() as $row) { 
                    $data[] = $row; 
                } 
            } 
            $Q->free_result(); 
            return $data;

        }

这是我的查询..我做了很多调整但它不会工作..等待可能的解决方案？谢谢

Answer 1

试试这个查询:

$this->db->select('
        questions.questions_id,
        questions.question_description,
        questions.question_explanation,
        questions.created_date,
        questions.updated_date,
        questions.is_active,
        diffLevels.difficulty_levels_title 
        ');
        $this->db->from("questions");
        $this->db->join("diffLevels",'questions.fk_difficulty_levels_id = diffLevels.preference' , 'inner');
        $this->db->where("questions.is_active",1);
        $query=$this->db->get();
        $data=$query->result_array(); 
        //echo $this->db->last_query();
        //echo "<hr/>";
        //echo "<pre>";
        //print_r($query);
        //exit;

我直接使用表名作为“questions”和“diffLevels”，请相应更改。