Slot: key

True means that the slot is the "singular unique key" (also known more simply as the "key slot") of its class. Such a slot uniquely identifies instances of the class within a single container, meaning there cannot be two (or more) instances of the class (or instances of any of its descendants) with the same value for the key slot within the container.

URI: linkml:key

Applicable Classes

Name	Description	Modifies Slot
SlotDefinition	an element that describes how instances are related to other instances	no

Properties

Type and Range

Property	Value
Range	Boolean
Domain	SlotDefinition
Domain Of	SlotDefinition

Cardinality and Requirements

Property	Value
### Slot Characteristics

Property	Value
Inherited	Yes

In Subsets

• SpecificationSubset
• BasicSubset
• RelationalModelProfile

Comments

• The key slot is inherited.
• A domain can have at most one key slot OR one identifier slot. However a domain can have both a key slot and any number of compound keys.
• A key slot is automatically required. Singular unique keys cannot be optional.
• The presence of a key slot makes a class eligible for inlining as a dictionary.

See Also

• https://linkml.io/linkml/schemas/constraints.html#singular-unique-keys
• https://linkml.io/linkml/schemas/inlining.html
• linkml:unique_keys
• linkml:identifier

Identifier and Mapping Information

Schema Source

• from schema: https://w3id.org/linkml/meta

Mappings

Mapping Type	Mapped Value
self	linkml:key
native	linkml:key

LinkML Source

name: key
description: True means that the slot is the "singular unique key" (also known more
  simply as the "key slot") of its class. Such a slot uniquely identifies instances
  of the class within a single container, meaning there cannot be two (or more) instances
  of the class (or instances of any of its descendants) with the same value for the
  key slot within the container.
comments:
- The key slot is inherited.
- A domain can have at most one key slot OR one identifier slot. However a domain
  can have both a key slot and any number of compound keys.
- A key slot is automatically required. Singular unique keys cannot be optional.
- The presence of a key slot makes a class eligible for inlining as a dictionary.
in_subset:
- SpecificationSubset
- BasicSubset
- RelationalModelProfile
from_schema: https://w3id.org/linkml/meta
see_also:
- https://linkml.io/linkml/schemas/constraints.html#singular-unique-keys
- https://linkml.io/linkml/schemas/inlining.html
- linkml:unique_keys
- linkml:identifier
rank: 1000
domain: slot_definition
inherited: true
domain_of:
- slot_definition
range: boolean