ThinkPHP AJAX分页实现与优化

function list_oa($type) {

                $oa_id = intval($_GET['oa_id']);
                if ($type == 'url')
                        $oa_id = intval($_GET['oa_id']);

                import("ORG.Util.Page");
                $st_sku = M("st_sku");


                $where = '';
                if ($oa_id != 0)
                        $where = ' and st_set.oa_id =  ' . $oa_id;
                $sql_c = " SELECT a.id  from 
(select st_set_list.id 
 from st_set_list   inner JOIN  st_set on st_set_list.set_id = st_set.id and st_set.is_set = 0 " . $where . ")as a 
inner join st_sku on a.sku_id  = st_sku.sku_id  
UNION ALL
SELECT st_set.id 
from st_set inner JOIN st_set_list on  st_set.is_set = 1 and st_set.id=st_set_list.set_id  " . $where . " GROUP BY st_set_list.set_id 

ORDER BY id desc";
                $count = count($st_sku->query($sql_c));
                $p = new Page($count, 20);

                $map['oa_id'] = $oa_id;

                foreach ($map as $key => $val) {
                        $p->parameter .= "$key=" . urlencode($val) . "&";
                }

//                $sql = 'SELECT sku_id,product FROM st_sku where sku_id in(select sku_id from st_set_list where set_id in(select id from st_set'. $where . ') ) order by sku_id desc';
//                $sql ='SELECT a.oa_id,st_sku.sku_id,st_sku.product from (select st_set_list.sku_id,st_set.oa_id from st_set_list   inner JOIN  st_set on st_set_list.set_id = st_set.id '.$where.')as a inner join st_sku on a.sku_id = st_sku.sku_id';
//                $sql = 'SELECT a.id,a.oa_id,a.amount,a.check_types_id,a.is_set,a.title,a.`status`,st_sku.sku_id,st_sku.product from 
//(select st_set_list.id,st_set_list.sku_id,st_set.oa_id,st_set.is_set,st_set.amount,st_set.check_types_id,st_set.title,st_set.`status`
// from st_set_list   inner JOIN  st_set on st_set_list.set_id = st_set.id  ' . $where . ' )as a 
//inner join st_sku on a.sku_id  = st_sku.sku_id order by a.id desc';

                $sql = "SELECT a.id,a.oa_id,a.amount,a.check_types_id,a.is_set,a.title,a.`status`,st_sku.product,st_sku.sku_id from 
(select st_set.id,st_set_list.sku_id,st_set.oa_id,st_set.is_set,st_set.amount,st_set.check_types_id,st_set.title,st_set.`status`
 from st_set_list   inner JOIN  st_set on st_set_list.set_id = st_set.id and st_set.is_set = 0 " . $where . ")as a 
inner join st_sku on a.sku_id  = st_sku.sku_id  
UNION ALL
SELECT st_set.id,st_set.oa_id,st_set.amount,st_set.check_types_id,st_set.is_set,
st_set.title,st_set.`status`,'',GROUP_CONCAT(st_set_list.sku_id)as sku_id
from st_set inner JOIN st_set_list on  st_set.is_set = 1 and st_set.id=st_set_list.set_id  " . $where . " GROUP BY st_set_list.set_id 

ORDER BY id desc limit " . $p->firstRow . ", " . $p->listRows;

                $sku_list = $st_sku->query($sql);
                foreach ($sku_list as &$sku) {
                        if ($sku['is_set'] == 0) {
                                $sku_prop = $this->get_sku_prop($sku['sku_id']);
                                $sku['sku_prop'] = $sku_prop;
                        } else {
                                $sku_ids = explode(',', $sku['sku_id']);
                                foreach ($sku_ids as $id) {
                                        $sku_prop = $this->get_sku_prop($id);
                                        $sku['sku_prop'] = $id.$sku_prop;