How to ensure that a column won't get overriden by a null value?

[sreejithraman]

Let's say I have a simple user table with the following columns: name, id, token.

Sometimes token is given to me and in those cases update token. Other times token will be null and in those cases I just want to keep the existing value inside token.

One way I thought of was to make a put resolver. Inside the resolver, I check if the given user already has a value for token. If it doesn't, I do a get based on the user's id. If i get a user back, I grab the token and save that along with the new user info.

But won't that basically double the amount of time to insert? I was wondering if there was a quicker way.

[nikitin-da]

To get rid inserting the same values, maybe just store token in separate table token : user_id, token_value?
Create put resolver like in one-to-many example with custom performPut. And here you can insert token only when it is needed and use two hidden resolvers for simple user and token.

[nikitin-da]

There is related issue #595

[nikitin-da]

For generated resolvers there is ignoreNull property (#642).
In custom resolver we should not put null to contentValues.