Help:Property constraints portal/Subject class

subject type constraint (Q21503250) specifies that items with a given property should have a given type. This is also known as the domain of a property.

For example, items with date of birth (P569) should be instance of (P31) human (Q5) or animal (Q729), and items with sRGB color hex triplet (P465) should be subclass of (P279) color (Q1075).

Subclass relations according to subclass of (P279) are taken into account: if a constraint demands that an item should be an instance of building (Q41176), it is not a violation if the item is an instance of skyscraper (Q11303), because there is a subclass of (P279) path from skyscraper (Q11303) to building (Q41176). (If an indirect relation should not be permitted, item-requires-statement constraint (Q21503247) can be used.)

If no constraint scope (P4680) is specified, this constraint is only checked on the main value of a statement.

Possible actions

There are several possible ways to address a violation of this constraint:

• It’s possible that the item should not have the statement at all, and that the statement should be removed.
• It’s possible that the item is missing the right instance of (P31) or subclass of (P279) statement.
• It’s possible that the item has the right instance of (P31) or subclass of (P279) statement, but the linked item is missing a subclass of (P279) statement. For example, if an item with population (P1082) was instance of (P31) big city (Q1549591), but big city (Q1549591) was missing subclass of (P279) city (Q515), then this could result in a violation on the item even though the error is actually on big city (Q1549591).
• It’s possible that the item is a rare, but legitimate exception to the constraint, and nothing should be done.

Parameters

This constraint has two parameters (both mandatory):

relation (P2309)

Must be instance of (Q21503252), subclass of (Q21514624), or instance or subclass of (Q30208840). Describes whether the item should be an instance of the class(es), or a subclass of it/them, or whether both are allowed. This parameter must only be given once.

class (P2308)

Lists the classes that the item should have. Each class must be an item ID (no value Help or unknown value Help is not permitted).

Examples

Example 1

Item which has place of birth (P19) data should be instance of human, fictional character or animal.

property constraint	subject type constraint edit class human fictional character animal relation instance of 0 references add reference
		add value

Example 2

Item which has drug or therapy used for treatment (P2176) data should be subclass of disease.

property constraint	subject type constraint edit class disease relation subclass of 0 references add reference
		add value

Template

When the constraint is set to the property, the following template is automatically displayed in the property talk page. The template is created by Module:Constraints using Template:Constraint, invoked from Template:Property documentation. Translations are defined at Module:i18n/constraints.

Type “human (Q5), fictional character (Q95074), person (Q215627)”: item must contain property “instance of (P31)” with classes “human (Q5), fictional character (Q95074), person (Q215627)” or their subclasses (defined using subclass of (P279)). (Help)

List of violations of this constraint: Database reports/Constraint violations/P512#Type Q5, Q95074, Q215627, hourly updated report, SPARQL

Lists

Lists of properties which are set type constraint.

• Category:Properties with constraints on type
• SPARQL query - click the execute button at the linked page to see the query result.