When to use `save` vs `save!` in model?

Question

According to save bang your head, active record will drive you mad, we should avoid using save! and rescue idiom for exceptional situations. Given that, say a model needs to @post.mark_rejected.

If the code in mark_rejected fails due to one of the below problems, should an exception be thrown? :

• if there is a validation problem
• if a non-nullable-field was being assigned a null
• if there was a connection loss to database

If we do not throw an exception, then:

• controller action would have to check for return value of mark_rejected and do it's thing
• we are not expecting an exception from that method call, so we do not write a rescue clause in the controller action, thus the exception bubbles up to (..wherever..) and will probably show up as some (500 HTTP?) error

Example code:

def mark_rejected   ...   save! end 

or

def mark_rejected   ...   save end 

Answer 1

save! will raise an error if not successful.

save will return boolean value like true or false.