I was asked a question the other day that at first glance seems to be a really simple question – but yet I didn’t immediately know the answer to it. Having got the answer I think it’s worth sharing. The question was:
“If a list item has its content type changed does it lose the field values if the fields are not in the new content type? i.e. will they still be there when or if the content type is changed back?”
The good news to this question is yes they do!
Here’s a (contrived) example – say you have a calendar list with a custom content called Work Event and Social Event. Say, Work Event has a field for Office Location.
We add an event of type Work Event – and then change it to Social Event. Looking at the properties for the item we see that the Office Location field is no longer there.
However, switching the content type back and viewing the properties we can see that the value for the Office field has been remembered!
[Thinking about this I suppose it’s obvious really. The content type is simply another value on the field – and the field values are what are available with the columns on the list.]