使用 codeigniter 模型加入查询

Question

请帮助我如何只在 activities.activity_id = response.activity_id 处得到响应？这是我的 CI_model

public function get_response(){
   
    $this->db->select('*');
    $this->db->from('response');
     $id = $this->session->userdata('id');
   $this->db->where_in('response.user_id', $id);
   $this->db->join('activities', 'response.activity_id = activities.activity_id');
     $this->db->join('users', 'users.id = response.user_id');
     
    $result = $this->db->get()->result_array();
    return $result;
}

My Activities table

My Response Table

My users table

Answer 1

试试这个：

$id = $this->session->userdata('id');

$this->db->select('a.*, b.*, c.*');
$this->db->join('activities b', 'a.activity_id = b.activity_id');
$this->db->join('users c', 'c.id = a.user_id');
$this->db->where_in('a.user_id', $id);

$result = $this->db->get('response a')->result_array();

return $result;

您需要为表添加别名以构建更简化和有序的查询，在本例中别名是 a、b 和 c。

更新：我修复了复制代码时错误编写的 get 方法。

检查此处共享的查询片段： https://extendsclass.com/mysql/526c246

希望对您有所帮助

使用 codeigniter 模型加入查询

Joining Query with codeigniter Model

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