如何從表2中獲取具有發送者和接收者名稱的所有數據，這些名稱與user（table1）表中的id鏈接

Question

我想顯示所有數據.. bt發送方和接收方的名稱存儲在用戶表中。 它們通過用戶ID鏈接到消息表。 現在，我需要為單行輸入兩個名稱。

public function all_transferData()
{
    $this->db->select('t.filename, t.message_subject, users.username, users.email');
    $this->db->from('transfer_history as t');
    $this->db->join('users', 't.sender_id = users.user_id');
    $query = $this->db->get();

    return $query->result();
}

Answer 1

您需要兩次聯接user表，一次聯接查詢發送方數據，另一次聯接查詢接收方數據。 如果receiver_id存儲在transfer_history表中，則可以嘗試以下操作：

    public function all_transferData()
    {
      $this->db->select('t.filename, t.message_subject, 
        su.username as sender_name, su.email as sender_email, 
        ru.username as receiver_name, ru.email as receiver_email');
      $this->db->from('transfer_history as t');
      $this->db->join('users as su', 't.sender_id = su.user_id');
      $this->db->join('users as ru', 't.receiver_id = ru.user_id');
      $query = $this->db->get();

      return $query->result();
    }