数组针对某项的求和问题
已知数组a：
<br> array (<br> 0 => <br> array (<br> 'stock_no' => 'SU13080800340',<br> 'adress' => 'B',<br> 'arr_time' => '2013-08-14 09:00:00',<br> 'c_type' => 'P32E',<br> 'cust_no' => '310F61VA5A',<br> 'mount_total' => '1',<br> 'total' => '16',<br> 'c1_time' => '2013-08-10 15:00:00',<br> 'packageno' => 'CVT121015001',<br> ),<br> 1 => <br> array (<br> 'stock_no' => 'SU13080800340',<br> 'adress' => 'B',<br> 'arr_time' => '2013-08-14 09:00:00',<br> 'c_type' => 'P32E',<br> 'cust_no' => '310F61VA5B',<br> 'mount_total' => '2',<br> 'total' => '32',<br> 'c1_time' => '2013-08-10 15:00:00',<br> 'packageno' => 'CVT121015002',<br> ),<br> 2 => <br> array (<br> 'stock_no' => 'SU13080800340',<br> 'adress' => 'B',<br> 'arr_time' => '2013-08-14 09:00:00',<br> 'c_type' => 'P32E',<br> 'cust_no' => '310F61VA5B',<br> 'mount_total' => '2',<br> 'total' => '32',<br> 'c1_time' => '2013-08-10 15:00:00',<br> 'packageno' => 'CVT121226001',<br> ),<br> )<br>
如何分别求得数组中的项cust_no对应的packageno的结果以及stock_no对应mount_total和total项求和的结果？
假设cust_no为310F61VA5A时，对应的packageno为CVT121225001。
cust_no为310F61VA5B时，对应的packageno为CVT121225002，CVT121226001。
stock_no为SU13080800340时，求得的mount_total结果为3（1+2），total结果为48（16+32）。
如何达到这样的效果？
