Wikidata:WikiProject sum of all paintings/External identifiers

We use described at URL (P973) and external identifiers to link to information about paintings. This identifier properties should be of type Wikidata property to identify artworks (Q44847669)

• Query for most used Wikidata property to identify artworks (Q44847669) on paintings
• Query for all Wikidata property to identify artworks (Q44847669) (some not used usually because it's for sculptures)

These properties can be used to help improve data completeness and data quality. All constraints should be present. If it triggers to many constraint violations, constraint status (P2316) set to suggestion constraint (Q62026391) can be added.

Common constraints

Constraints to have in property constraint (P2302).

Constraint	Qualifiers	Most common status	Missing query	Description
format constraint (Q21502404)	format as a regular expression (P1793)	mandatory constraint (Q21502408)	query	To make sure it's a valid identifier that will produce a valid url.
single-value constraint (Q19474404) / single-best-value constraint (Q52060874)		mandatory constraint (Q21502408)	query	Only one (preferred) value per item. polyptych (Q1278452) often messes this up.
distinct-values constraint (Q21502410)		mandatory constraint (Q21502408)	query	To make sure the value is unique and not used by multiple items. polyptych (Q1278452) often messes this up.
subject type constraint (Q21503250)	class (P2308) -> painting (Q3305213)/work of art (Q838948)/object (Q488383) relation (P2309) -> instance of (Q21503252)	normal	query	To make sure it's used on the right types of objects. Choice very much depends on the property.
allowed-entity-types constraint (Q52004125)	item of property constraint (P2305) -> Wikibase item (Q29934200)	normal	query	Generally only used on Wikibase items
property scope constraint (Q53869507)	property scope (P5314) -> as main value (Q54828448) & as reference (Q54828450)	normal	query	Usually it can be used as a regular statement and as part of a reference
label in language constraint (Q108139345)	Wikimedia language code (P424) -> Source language of the property	normal	query	All items should have labels and usually the source of the property provides the label in one or more languages

item-requires-statement constraints

The constraint property constraint (P2302) -> item-requires-statement constraint (Q21503247) makes sure a certain property is also set on items using the identifier property. The qualifier property (P2306) is set to the property that should be present.

Property	Most common status	Missing query	Description
creator (P170)	normal	query	Artwork should have a creator
inception (P571)	normal	query	Artwork should have an inception
collection (P195)	normal or mandatory constraint (Q21502408)	query	Every artwork should have one or multiple collection statements. On collection specific properties the qualifier item of property constraint (P2305) is added set to the collection and status set to mandatory.
inventory number (P217)	normal or suggestion constraint (Q62026391)	query	Most works of art will have one or multiple inventory numbers
location (P276)	normal or mandatory constraint (Q21502408)	query	Every artwork should have one or multiple location statements. On collection specific properties the qualifier item of property constraint (P2305) might be added.
made from material (P186)	suggestion constraint (Q62026391)	query
genre (P136)	suggestion constraint (Q62026391)	query
depicts (P180)	suggestion constraint (Q62026391)	query
height (P2048)	suggestion constraint (Q62026391)	query
width (P2049)	suggestion constraint (Q62026391)	query
copyright status (P6216)	suggestion constraint (Q62026391)	query

See the property statistics to get an idea of completeness.