Help:Special property "Subproperty of"
| Subproperty of | |
|---|---|
| Lets you indicate that one property is a subproperty of another | |
| Further Information | |
| Provided by: | Semantic MediaWiki |
| Added: | 1.0 |
| Removed: | still in use |
| Alias: | has no alias |
| Is optional: | no |
| Label: | not specified |
| Focus: | not specified |
| In this wiki: | Property:Subproperty of |
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 subproperties ("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 subproperties since SMW 1.2.1. 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 won't appear in Special:Properties (or will appear with a caution This property is hardly used within the wiki!).
See the property page Subproperty of to see which pages use this special property on this wiki.
