Mysql 带左联接的SQL查询中的限制

I mam SQL Query to me读取类别，我们想做分页类别也使用SQL Query to me其语句：

public function fetchChildrenNodess($start,$end){
        $q_offset = (int)$start;
        $q_limit = (int)($end - $start);

$query= "select k1.id as id from ".Config::tableKategorie." k1 left join ".Config::tableKategorie."  k2 on k2.nlft<k1.nlft and k2.nrgt>k1.nrgt and k2.nlft>".$this->L." and k2.nrgt<".$this->R." where k1.nlft>".$this->L." and k1.nrgt<".$this->R." and k2.id is null  order by k1.nlft ";

         $i=0; $ret=array();
        // $hash=$this->hash().'_part_'.$start.'_'.$end;


             $Q=mysql_query($query."LIMIT 0, 8 ",CommerceDB::$DB);
             while($R=mysql_fetch_assoc($Q)){
                 $ret[]=new Kategoria($R['id']);

         };

         return $ret;





    }

---

所以我只列出了9个子类别，然后转到下一个子类别。子类别也包括9个类别。我需要得到我的清单只包括最多8个结果。谢谢你在这个解决方案中，你的函数应该只有一个参数，你可以增加next或者减少prev。我假设您的查询和其他代码工作正常

页面参数的顺序为1-N。如果目标是将记录集限制为8行，则不要让用户指定结束值

public function fetchChildrenNodess($page){

   $range_const = 8; // # of rows to show; constant value

   if( $page > 0 ) // what if page is 0 or less ???
       $start = ($range_const * ($page-1)); // start limit
   else
       $start = 0;

   $end = $range_const - $start; // end limit

   $query= "select k1.id as id from ".Config::tableKategorie." k1 left join ".Config::tableKategorie."  k2 on k2.nlft<k1.nlft and k2.nrgt>k1.nrgt and k2.nlft>".$this->L." and k2.nrgt<".$this->R." where k1.nlft>".$this->L." and k1.nrgt<".$this->R." and k2.id is null  order by k1.nlft ";
   $query = $query . ' LIMIT ' . $start . ',' . $end . ';'

   $i=0; $ret=array();

   $Q = mysql_query($query,CommerceDB::$DB);
   while($R=mysql_fetch_assoc($Q)){
       $ret[]=new Kategoria($R['id']);
   }
}

测试用例

public function fetchChildrenNodess($page){

   $range_const = 8; // # of rows to show; constant value

   if( $page > 0 ) // what if page is 0 or less ???
       $start = ($range_const * ($page-1)); // start limit
   else
       $start = 0;

   $end = $range_const - $start; // end limit

   $query= "select k1.id as id from ".Config::tableKategorie." k1 left join ".Config::tableKategorie."  k2 on k2.nlft<k1.nlft and k2.nrgt>k1.nrgt and k2.nlft>".$this->L." and k2.nrgt<".$this->R." where k1.nlft>".$this->L." and k1.nrgt<".$this->R." and k2.id is null  order by k1.nlft ";
   $query = $query . ' LIMIT ' . $start . ',' . $end . ';'

   $i=0; $ret=array();

   $Q = mysql_query($query,CommerceDB::$DB);
   while($R=mysql_fetch_assoc($Q)){
       $ret[]=new Kategoria($R['id']);
   }
}

+----------+--------+------+ | Page Num | $start | $end | +----------+---------------+ | 1 | 0 | 8 | | 2 | 8 | 8 | | 3 | 16 | 8 | | 4 | 24 | 8 | | | | | | 0 | 0 | 8 | | -1 | 0 | 8 | +----------+--------+------+