relates
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This documentation is not current - it is for TypeDB 2.x, which is no longer supported. View the documentation for TypeDB 3.x: |
The relates keyword is used in TypeQL schema to define a role of a relation type.
Syntax
The syntax of a relates statement includes:
-
Subject — type label of a relation type
-
Predicate — the
relateskeyword -
Object — type label of a role
<relation-type> relates <role> [as overridden-type];An optional override can be added at the end.
Behavior
TypeQL statements with the relates keyword can be used only in Define and Undefine queries.
The relates keyword adds a new role to a relation type.
Usage in a schema definition
For this example, use a database with the IAM schema and sample data loaded.
Since in Define and Undefine queries you can’t use variables, both subject and object can only be type labels.
For example, to define a new role subject for the permission relation type, use:
define
permission relates subject;To remove the new role, use:
undefine
permission relates subject;Usage with override
By default, a subtype of a relation type inherits all roles that were defined for its supertype.
To override an inherited role, use the as keyword.
Let’s see an example, of a schema, where the owned role of the ownership relation type gets overridden by
the object role:
define
object-ownership sub ownership,
owns ownership-type,
relates object as owned;