Google Datastore (NoSQL) backend for PHP CMS I am working on a personal project where I am creating a small CMS using PHP as the developing language, but I want to be able to deploy it to the Google App Engine and I want to use its Google Datastore (NoSQL).

The question I have is how to do relationship between kinds?

For example:


Kind 1: call category 
Kind 2: call tags 
Kind 3: call post


I want the posts to be able to have one category, but multiple tags. I am having trouble visualizing it. I am coming from SQL world so having the ID of the category and the IDs of the tags to them JOIN them will take care of the same issue.

Note: if there is some tutorial or reading that you could share I will appreciate it.
Try this link https://cloud.google.com/appengine/docs/php/storage . This should get you started on the use and main concepts.
FYI joins are not applicable to the datastore but if you model out your data correctly you should have no problem.