将 mysql 查询转换为 codeigniter 3 模型

Question

将 MySQL 查询转换为 Codeigniter 查询

    $query = "(SELECT content, title, 'msg' as type FROM messages WHERE content LIKE '%" . 
               $keyword . "%' OR title LIKE '%" . $keyword ."%') 
               UNION
               (SELECT content, title, 'topic' as type FROM topics WHERE content LIKE '%" . 
               $keyword . "%' OR title LIKE '%" . $keyword ."%') 
               UNION
               (SELECT content, title, 'comment' as type FROM comments WHERE content LIKE '%" . 
               $keyword . "%' OR title LIKE '%" . $keyword ."%')";

    mysql_query($query);

我试图在 Codeigniter 中转换它

              $this->db->like("content", $keyword);

              $this->db->or_like('title',$keyword,'after'); 
              $this->db->or_like('msg',$keyword,'after'); 
             ->from('message')
              $this->db->like("content", $keyword);
              $this->db->or_like('title',$keyword,'after'); 
              $this->db->like("msg", $keyword);
             ->from('topics')
              $this->db->or_like('content',$keyword,'after'); 
              $this->db->or_like('title',$keyword,'after'); 
              $this->db->or_like('msg',$keyword,'after'); 
              ->from('comment')

最上面的一个在 MySQL 中，我尝试转换的底部在 Codeigniter 我试图从三个表的选定列中搜索关键字。 如何将 MySQL 转换为 Codeigniter。 我正在尝试从三个表的选定列中搜索关键字。

我如何将 MySQL 转换为 Codeigniter

Answer 1

尝试这个

$this->db->select('content, title, msg as type');
$this->db->from('message');
$this->db->like("content", $keyword);
$this->db->or_like('title',$keyword,'after'); 
$this->db->or_like('msg',$keyword,'after'); 
$query1 = $this->db->get_compiled_select();


$this->db->select('content, title, msg as type');
$this->db->from('topics');
$this->db->like("content", $keyword);
$this->db->or_like('title',$keyword,'after'); 
$this->db->like("msg", $keyword);
$query2 = $this->db->get_compiled_select();

$this->db->select('content, title, msg as type');
$this->db->from('comment');
$this->db->or_like('content',$keyword,'after'); 
$this->db->or_like('title',$keyword,'after'); 
$this->db->or_like('msg',$keyword,'after'); 
$query3 = $this->db->get_compiled_select();

$result = $this->db->query($query1." UNION ".$query2." UNION ".$query3);
return $result->result();

注意：-如果您打算使用它，请确保您的两个表列具有相同的序列和名称。