Cakephp How to query the paid amount?

问题

I dont know whats wrong but my code dont output the paid amount column

$payment_tbl = TableRegistry::get("MembershipPayment");
$payments = $payment_tbl->find();
$payments->select(['payment_total'=> $payments->func()->sum('paid_amount')]);
$this->set("payments",$payments);

and then echo this as echo $payments->payment_total;

回答1:

$payments will be a query result object, not a single result. With this query, where you're expecting just a single row, add ->first() after your sum call.

In general, if you're not getting what you expect, dump the contents of the variable in question, like with pr($payments) or debug($payments), that will very often very quickly give you a clear indication of what the problem is. In this case, you'll see it's not the Entity object that you're expecting.

来源：https://stackoverflow.com/questions/61278984/cakephp-how-to-query-the-paid-amount