如何在代码点火器中编写以下代码

Question

SELECT *, FROM location WHERE date IN (SELECT MAX(date) 
FROM location GROUP BY user detail id);  

我已经为上述代码编写了代码，但是没有用。这是代码：

$this->db->order_by("date","desc");
$select= $this->db->select('*');
$this->db->group_by('userdetail_id');
$this->db->limit(1);  $qry = $this->db->get('location');

Answer 1

您可以按照以下方式写

$this->db->select('*');  
$this->db->where("date IN (SELECT MAX(date) FROM location GROUP BY userdetail_id) ",false,false);  
$this->db->limit(1);  
$this->db->order_by("date","desc");  
$qry = $this->db->get('location'); 

Answer 2

查询应为：

    $this->db->select("*");
    $this->db->where_in("(SELECT MAX(date) FROM location GROUP BY userdetail_id)");
    $this->db->order_by("date","desc");
    $this->db->get('location')