Help:Property constraints portal/One of

one-of constraint (Q21510859) specifies that only certain values are allowed for a property. Its opposite is none-of constraint (Q52558054).

For example, the only valid values for driving side (P1622) are left (Q13196750) and right (Q14565199).

If no constraint scope (P4680) is specified, this constraint is checked everywhere.

If such a constraint is defined on a property, its values are also used as suggestions when someone adds a new statement with that property. For example, someone adding a new driving side (P1622) statement will see the allowed values (left (Q13196750), right (Q14565199)) as suggestions. (Other values can still be added by searching for them or pasting their item IDs.)

Possible actions

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

  • It is possible that the value is erroneous, and one of the allowed values should be used instead, e. g. left (Q13196750) (direction) instead of left-wing (Q164597) (political term, has the same label in some languages).
  • It is possible that the statement is incorrect and should be removed.
  • It is possible that the item is a rare, but legitimate exception to the constraint, and nothing should be done.

Parameters

This constraint has one mandatory parameter:

item of property constraint (P2305)
Contains the allowed values. no value Help and unknown value Help are interpreted literally, like any normal value (statements with no value Help or unknown value Help are only allowed if these special values are also given in the allowed values).

Examples

Example 1

Example setting for driving side (P1622).

property constraint
  one-of constraint
item of property constraint left
right
constraint status mandatory constraint
0 references
add reference


add value

Example 2

Example setting for disabled accessibility (P2846).

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.

constraint “one-of constraint (Q21510859)” declaration error: “Module:Constraints/search:24: attempt to index a nil value”.

Lists

Lists of properties which are set one-of constraint.