求助两道面试题

第一题：计算某个表新插入记录的id值（id为主键），不用mysql本身的自增id策略而采用memcached，假设key值不会丢失，请指出方法2错在哪里。
方法1：

$lastInsertId = $memcacheObj->increment($key);

      return $lastInsertId;

方法2：

$lastInsertId = $memcacheObj->get ($key);

	 $lastInsertId++；

	 $memcacheObj->set($key，$lastInsertId);

	 return $lastInsertId;

第二题：为这段代码找错

$nowdate=date('Y-m-d');

$olddate=date('Y-m-d',strtotime('-7 days'));	

$table=date('Ym');

$reltable='readerorder_master_'.$table;	

$sql1="SELECT novelid, sendmoneydate, sum( jj_point ) AS jj FROM {$reltable} WHERE STATUS =2 AND sendmoneydate BETWEEN '".$olddate."' AND '".$nowdate."' GROUP BY novelid ORDER BY jj DESC limit 1,500";	

$DBM = new Net_Config_Database(Net_Config_Database::vip_moneyMaster); 

$query1=$DBM->query($sql1);

$novelIDs = array();

while($relult1 = $DBM->fetch_array($query1)){

   $novelIDs[]=$relult1['novelid'];

}

$stronglyIndex1 = array();

$nums=0;

foreach($novelIDs as $value){

$sql2="SELECT a.authorid,a.authorname,n.novelname,n.novelid, ebookurl as coverImg ,n.vip_flag

      FROM novelinfo n,author a,novel_class_1 b

	  WHERE n.authorid=a.authorid and n.novelid = b.novelid and b.yc in(1,2) and xx in(2,3) and n.vip_flag=1 and n.vip_month_flag=0

	  AND n.novelid={$value}";	

$query = mysql_query($sql2, $connect);

$result2 = mysql_fetch_array($query);

if($result2['vip_flag'] == 1 && $nums < 10){

 $stronglyIndex1[] = $result2;

 $nums++;

 }

 }