Special property "Subproperty of"

Editing Properties and typesSpecial properties

Subproperty of
Lets you indicate that one property is a subproperty of another
Further Information
Provided by:	extension "Semantic MediaWiki "Allows to store and query data annotated to pages
Added:	1.0
Removed:	still in use
Alias:	has no alias
Optional:	no
Visible:	yes
Annotable:	yes
Declarative:	yes
Key:	_SUBP
Setting:	not specified
Focus:	not specified
In this wiki:	Property:Subproperty of
Table of Contents

The Subproperty of property is a special property in Semantic MediaWiki with a built-in meaning: it lets you indicate that one property is a subproperty of another.

It means that a query for pages with the property should also return pages that have the subproperty. For example, querying for the property "spouse" should also find pages with the properties "wife" and "husband", if those properties have the special property [[Subproperty of::Spouse]]. You can query on all subproperties by querying on the head property. For instance,

{{#ask:
 [[Spouse::+]]
}}

returns all pages that use the head property ("spouse") and its subproperties ("wife" and "husband"). If the head property is chosen for an additional printout statement in a query, the corresponding results will be the values of the head property only. To ensure that those of its subproperties are included as well, the relevant subproperties must be explicitly specified. For instance,

{{#ask:
 [[Spouse::+]]
 |?Spouse
 |?Wife
 |?Husband
}}

will print the values of the head property ("spouse") as well as those of the two sub-properties ("wife" and "husband").

On systems where the first letter of an article does not get capitalized make sure that the property is maintained with an capital S [[Subproperty of::Spouse]] otherwise the system does not recognize it as a special property.

This special property also agrees with rdfs:subPropertyOf:

If property P is a subproperty of property P', then all pairs of resources which are related by P are also related by P'.

Notes

• A property's page shows its sub-properties since Semantic MediaWiki 1.2.1Released on 8 August 2008 and compatible with MW 1.11.x - 1.14.x.. The page of the head property does not, however, list the values of its subproperties.
• If no pages (or very few pages) in the wiki use a property, then even if lots of pages use its subproperties:
  • The property's page will list no (or few) pages under "Pages using the property"
  • The property will not appear in Special:Properties (or will appear with a caution This property is hardly used within the wiki!).
• Starting with Semantic MediaWiki 3.1.0Released on 23 September 2019 and compatible with MW 1.31.0 - 1.33.x. it is possible to enforce that the subproperty uses the same datatype as the parent property1. See the help page on mandatory parent datatype inheritance for further information.

See also

• Help page on subproperty inferencing
• Help page on mandatory parent datatype inheritance
• Help page on configuration parameter $smwgQSubpropertyDepthSets the maximum level of subproperty inclusion (steps within property hierarchy)
• Property page Subproperty of to see which pages use this special property on this wiki.