Moved from GitHub dgraph/4085
Posted by campoy:
It is confusing that when you declare a field in a type this is not taken into account automatically by the schema.
What you wanted to do
In issue #4080, a user created a type with a field
head of type
uid to keep a 1:1 relationship.
What you actually did
Since they didn’t create the corresponding predicate in the schema
head: uid ., once they sent the first mutation with a
head predicate pointing to a
uid, the predicate was created.
The problem is this predicate was created with type
head: [uid] . therefore breaking the user’s expectations.
Why that wasn’t great, with examples
This made the user think 1:1 relationships were not supported.
Their expectations were justified.
Instead, I would have expected that if you create a type with field
head uid in a type a corresponding predicate would be created.
This also includes the fact that if two types are created with the same name but different types an error should be returned.
Any external references to support your case