is the model layer of MVC not an exception to throw??

I was told that the design model layer for MVC should not do anything wrong. These actions should be done by C. "

Is that the case? Why can't the M layer throw an exception? I don't understand.

Reply to discussion (solution)

It's not a rule.

But there is some truth to what he says, model is business logic, and if model is abnormal, then the whole process is wrong.
Of course he said: When the model appears abnormal, only throw, not processing. Handing over to Controller

The control layer invokes the Model business logic return value and makes a corresponding throw exception.

That's absolutely true. There is no standard for such things. The M layer can also throw exceptions.

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