将SQL查询转换为codeigniter活动记录

Question

I am working on a private message app using CodeIgniter.
I have 3 tables:

1. conversations
2. conversations_messages
3. conversations_members.

I am trying to join the tables by matching the conversations ids and fetch all the messages for the user who's logged in.

This is the standard sql query

    SELECT 
    'conversations','conversation_id',
    'conversations','conversation_subject',
    MAX('conversations_messages','message_date') AS 'conversation_last_reply'
FROM 'conversations'
LEFT JOIN 'conversations_messages' ON 'conversations'.'conversation_id' = 'conversations_messages'.'conversation_id'
INNER JOIN 'conversations_members' ON 'conversations'.'conversation_id' = 'conversations_members'.'conversation_id'
WHERE 'conversations_members', 'user_id' = $sender_id
AND 'conversations_members','conversation_deleted' = 0
GROUP BY 'conversations'.'conversation_id'
ORDER BY 'conversation_last_reply'  DESC";

Its a big query, hence; I'm not sure how to convert it to CodeIgniter active records or simply make it run with the framework.

Any corrections would be appreciated too.

Answer 1

Try below code with CodeIgniter active record.

 $this->db->select('conversations, conversation_id, conversation_subject');
 $this->db->select_max('conversations_messages.message_date', 'conversation_last_reply');
 $this->db->from('conversations');
 // Joining with conversations_messages table 
 $this->db->join('conversations_messages','conversations.id=conversations_messages.conversation_id','left');
 $this->db->join('conversations_members','conversations.id= conversations_members.conversation_id','inner');
 $this->db->where('conversations_members.user_id',$sender_id);
 $this->db->where('conversations_members.conversation_deleted','0');
 $this->db->group_by('conversations.conversation_id');
 $this->db->order_by('conversation_last_reply');
 // Get the results from db
 $query = $this->db->get();
 // Result array contains the records selected
 $result_array = $query->result_array();

Happy coding

Naseem

Answer 2

 $this->db->select('conversations, conversation_id, conversation_subject');
 $this->db->select_max('conversations_messages.message_date', 'conversation_last_reply');
 $this->db->from('conversations');
 // Joining with conversations_messages table 
 $this->db->join('conversations_messages','conversations.id=conversations_messages.conversation_id','left');
 $this->db->join('conversations_members','conversations.id= conversations_members.conversation_id','inner');
 $this->db->where('conversations_members.user_id',$sender_id);
 $this->db->where('conversations_members.conversation_deleted','0');
 $this->db->group_by('conversations.conversation_id');
 $this->db->order_by('conversation_last_reply');
 // Get the results from db
 $query = $this->db->get();
 // Result array contains the records selected
 $result_array = $query->result_array();