MySQL在codeigniter中加入两个表查询

I have two table, limit and transaction enter image description hereenter image description here

        $wherehis= array('status'=>'Yes','company_id' =>$compnayid);
        $this->db->select('type,tra.amount,tra.qty,limit_id');
        $this->db->where($wherehis);
        $this->db->limit(100);
 $this->db->order_by('tra.tra_id','DESC');
        $this->db->join('limit_history as sell', 'tra.sell_limit_id = sell.limit_id','left');
        $this->db->join('limit_history as buy', 'tra.buy_limit_id = buy.limit_id','left');
        $data['Histroy']= $this->db->get("tbltrancation as tra")->result_array();

but get only sell order....please help me thanx

get the buy and sell both data

enter image description here

Try this,

    $this->db->limit(100);
    $this->db->order_by('tra.tra_id','DESC');
    $this->db->join('limit_history as sell', '(tra.sell_limit_id = sell.limit_id AND tra.buy_limit_id = buy.limit_id)','left');
    $data['Histroy']= $this->db->get("tbltrancation as tra")->result_array();

When there are identical column names you need to give them an alias to differentiate them:

$this->db
    ->select('tra.*, sell.amount as sell_amount, sell.qty as sell_qty, buy.amount as buy_amount, buy.qty as buy_qty')
    ->from('tbltrancation as tra')
    ->join('limit_history as sell', 'tra.sell_limit_id = sell.limit_id', 'left')
    ->join('limit_history as buy', 'tra.buy_limit_id = buy.limit_id', 'left')
    ->order_by('tra.tra_id', 'desc')
    ->limit(100);

$data['Histroy'] = $this->db->get()->result_array();