这是我数据库的结果集print_r($plan);Array([0]=>Array([id]=>2[subscr_unit]=>D[subscr_period]=>[subscr_fee]=>)[1]=>Array([id]=>3[subscr_unit]=>M,Y[subscr_period]=>1,1[subscr_fee]=>90,1000)[2]=>Array([id]=>32[subscr_unit]=>M,Y[subscr_period]=>1,1[subscr_fee]=>150,1500))如何将$plan[0]更改为$plan[value_of_id]谢谢。