Related models are updated on Update() even if no related columns are specified

[roobre]

If a model has relations, they will be saved after calling parentStore.Update(parent, Schema.Parent.PlainString), even if their FKs are not included in the cols... list.

This behaviour is not breaking, but kind of suboptimal. Most of the time you specify which columns must be updated it's because you don't want to touch any other thing.

It can be considered problematic if the user assumes that only the specified fields will be updated.

[niondir]

This is similar to the issues discussed in: #232 #211 #214 #219

[roobre]

I'm inclined towards changing kallax behaviour to this, but the change might be seen as breaking. The documentation does not state this behaviour clearly, but some users might be relying on this "feature".

Depending on how #219 is addressed, this may or may not be required. If this were to happen, it should be on version 2.0 to avoid breaking existing user code.

[Azuka]

Hi. I just wanted to check on this as I'm seeing strange side effects.