CI分页双查询

Question

我正在CI框架中工作。对于分页，我使用两个查询，一个用于需要的输出使用限制，另一个用于计算总行数。是否有任何其他方式可以完成单个查询？ 我的查询是：

{ 
$searchtxt = $this->input->post('searchtxt'); 
     $datefrom = $this->input->post('fromdate'); 
     $todate = $this->input->post('todate'); 
     $status= $this->input->post('order_status'); 
     $sc_id = $this->input->post('sc_id'); 



    if($sc_id){ 
     $this->db->where('('.'o.requested_sc_id = '.$sc_id.' OR o.requesting_sc_id = '.$sc_id.')'); 


     //$this->db->where('o.requesting_sc_id =',$sc_id); 
     } 

    if ($status){ 
     $this->db->where('o.order_status =',$status); 
     } 
     if ($status != '' && $status == 0){ 
     $this->db->where('o.order_status = 0'); 
     } 
    if($searchtxt){ 
     $this->db->like('o.order_number',$searchtxt); 
    } 
    if($datefrom) 
    {   
     $this->db->where('o.order_dt >=', date("Y-m-d",date_to_timestamp($datefrom))); 
    } 

    if($todate) 
    {   
     $this->db->where('o.order_dt <=', date("Y-m-d",date_to_timestamp($todate)));  
    } 
    if ($this->session->userdata('usergroup_id')!=1 && $this->session->userdata('usergroup_id')!= 2 && $this->session->userdata('usergroup_id')!=6){  

     $this->db->where('('.'o.requested_sc_id = '.$this->session->userdata('sc_id').' OR o.requesting_sc_id = '.$this->session->userdata('sc_id').')'); 
     //$this->db->where('o.requesting_sc_id = '.$this->session->userdata('sc_id')); 
    } 

    $this->db->select('o.order_id,o.order_number,o.order_dt,o.call_id,c.call_uid,o.order_status,o.order_dt,sc.sc_name,e.engineer_name'); 
    $this->db->from($this->table_name.' AS o'); 
    $this->db->join($this->mdl_callcenter->table_name.' AS c','c.call_id=o.call_id','left'); 
    $this->db->join($this->mdl_servicecenters->table_name.' AS sc' ,'sc.sc_id=o.requested_sc_id','left'); 
    $this->db->join($this->mdl_engineers->table_name.' AS e', 'e.engineer_id = o.engineer_id','left'); 
    $this->db->order_by('o.order_status ASC,o.order_dt DESC,o.order_created_ts DESC'); 
    if(isset($page['limit'])){ 
     $this->db->limit((int)$page['limit'],(int)$page['start']); 
    } 

    $result = $this->db->get(); 
     //echo $this->db->last_query(); 
    if ($status){ 
     $this->db->where('o.order_status =',$status); 
     } 
    if ($status != '' && $status == 0){ 
     $this->db->where('o.order_status = 0'); 
     } 
    if($sc_id){ 
     $this->db->where('o.requesting_sc_id =',$sc_id); 

     } 
    if($searchtxt){ 
     $this->db->like('o.order_number',$searchtxt); 
    } 
    if($datefrom) 
    {   
     $this->db->where('o.order_dt >=', date("Y-m-d",date_to_timestamp($datefrom))); 
    } 

    if($todate) 
    {   
     $this->db->where('o.order_dt <=', date("Y-m-d",date_to_timestamp($todate)));  
    } 
    //if ($this->session->userdata('global_admin')!=1){  
    if ($this->session->userdata('usergroup_id')!=1 && $this->session->userdata('usergroup_id')!= 2 && $this->session->userdata('usergroup_id')!=6){ 
     $this->db->where('o.requested_sc_id = '.$this->session->userdata('sc_id').' or o.requesting_sc_id = '.$this->session->userdata('sc_id')); 
    } 
    $this->db->select('o.order_id'); 
    $this->db->from($this->table_name.' AS o'); 
    $this->db->join($this->mdl_callcenter->table_name.' AS c','c.call_id=o.call_id','left'); 
    $this->db->join($this->mdl_servicecenters->table_name.' AS sc' ,'sc.sc_id=o.requested_sc_id','left'); 
    $this->db->join($this->mdl_engineers->table_name.' AS e', 'e.engineer_id = o.engineer_id','left'); 
    $result_total = $this->db->get(); 

    $orders['list'] = $result->result(); 
    $orders['total'] = $result_total->num_rows(); 
    return $orders; 
} 

Answer 1

下面是对此的一些解释。

function($limit,$offset){ 

    $this->db 
      ->select("SQL_CALC_FOUND_ROWS emp", FALSE) 
      ->select("*") 
      ->from('tbl1') 
      ->limit($limit, $offset); 

    $data["query_result"] = $this->db->get()->result_array(); 

    $query = $this->db->query('SELECT FOUND_ROWS() AS `Count`'); 
    $data["total_rows"] = $query->row()->Count; 

    return $data; 
} 

在这里你看到你被迫使用另一个查询来获得总数。
当然这不是你想要的，但使用mysql的单个查询是不可能的。
但这里是一个PHP方式。

function($limit,$offset){ 

    $this->db 
      ->select("*") 
      ->from('tbl1'); 

    $data["query_result"] = $this->db->get()->result_array(); 
    $data["total_rows"] = array_slice($data["query_result"], $offset, $limit); 

    return $data; 
} 

这可以用单一的查询来实现，但是包括PHP来获得所需的结果。