What is the difference between a Controller and a Facade?

Normally it would be the other way around, as you tend to have fewer facades in your system then controllers. Facades are meant to be wrappers around complex functionality, their primary goal is hiding complexity of an underlying system. You can think of the Facade as a layer wrapping the complex functionality and providing simpler methods to interact with.

A controller, on the other hand, is normally tied to a very specific piece of functionality in the system. It's main goal is to mediate the interaction between a view and a model, or in some cases just a model.

It's more typical to have a facade interacting with several controllers, than vice versa.

Chrome DevTools->Network,to check the HTTP request header

Aggregates | 聚合： count、max、min、avg 、 sum。

SQL的JOIN语法，感觉会用到，两个表的各种交集并集etc：

paradigm | 范式 ：