Help:Property constraints portal/Inverse
This is the documentation page for a particular constraint type. See Help:Property constraints portal for a general overview of property constraints. |
inverse constraint (Q21510855) specifies that a property has an inverse property, and values for the property should have a statement with the inverse property pointing back to the original item.
For example, mother (P25) has the inverse property child (P40): if the statement Jesus (Q302)mother (P25)Mary (Q345) exists, then the inverse statement Mary (Q345)child (P40)Jesus (Q302) should also exist.
If no constraint scope (P4680) is specified, this constraint is only checked on the main value of a statement. This is also the only currently supported scope.
Possible actions
[edit]There are several possible ways to address a violation of this constraint:
- The most likely case is that the inverse statement should be added to the other item, where it is missing. As there may be many such cases, a frequent approach is to do this by bot.
- It’s possible that the current item should not have the statement at all, and that the statement should be removed.
- It’s possible that the item is a rare, but legitimate exception to the constraint, and nothing should be done.
Parameters
[edit]This constraint has one mandatory parameter:
- property (P2306)
- Contains the inverse property. Must contain exactly one property (no value Help or unknown value Help is not permitted).
Example
[edit]Example setting for mother (P25).
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Template
[edit]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.
if [item A] has this property (mother (P25)) linked to [item B],
then [item B] should also have property “child (P40)” linked to [item A]. (Help)
List of violations of this constraint: Database reports/Constraint violations/P25#inverse, SPARQL
Lists
[edit]Lists of properties which are set inverse constraint.
- Category:Properties with inverse constraints
- SPARQL query - click the execute button
at the linked page to see the query result.