php - codeigniter查询问题

Question

此代码在 mysql run 命令中完美运行

SELECT employeeCode
FROM employee_details
WHERE employeeCode
IN (
    SELECT DISTINCT (employeeCode) FROM quiz_answer_detailsWHERE submitTime
    IN (SELECT MIN( submitTime ) FROM quiz_answer_details WHERE quizId
    IN (SELECT id FROM quiz_details WHERE uploadtime =  '2014-04-03')
    AND answer IN (SELECT answer FROM quiz_details WHERE uploadtime =  '2014-04-03'))
   )

但是我想在我的 codeigniter 上使用此代码，但它不起作用。

我的 codeigniter 查询代码是

    $this->db->select('employeeCode');
    $this->db->from('employee_details');
    $this->db->where_in('employeeCode');
    $this->db->select('DISTINCT(employeeCode)');
    $this->db->from('quiz_answer_details');
    $this->db->where_in('submitTime');
    $this->db->select('min(submitTime)');
    $this->db->from('quiz_answer_details');
    $this->db->where_in('quizId');
    $this->db->select('id');
    $this->db->from('quiz_details');
    $this->db->where('uploadtime',"2014-04-03");
    $this->db->where_in('answer');
    $this->db->select('answer');
    $this->db->from('quiz_details');
    $this->db->where('uploadtime',"2014-04-03");
    $query=$this->db->get();
    print_r($query);
    if($query->num_rows>=1)
    {
        return $query;
    }
    else
    {
         return false;
    }

出了什么问题请帮帮我

Answer 1

问题出在这段代码以及随后类似的 where_in 用法

$this->db->where_in('employeeCode');

您已给出where参数值，但未给出匹配对象。
例如。

$this->db->where_in('employeeCode',$subQuery1);

---

documentation where_in:

$this->db->where_in();

Generates a WHERE field IN ('item', 'item') SQL query joined with AND if appropriate

$names = array('Frank', 'Todd', 'James'); $this->db->where_in('username', $names); // Produces: WHERE username IN ('Frank', 'Todd', 'James')

---

您必须为每次调用 where_in 创建一个单独的子查询。