Property talk:P2436
Latest comment: 5 years ago by Deryck Chan in topic Not qualifier only
Documentation
voltage
difference in electric potential between two points (indicated in volt)
difference in electric potential between two points (indicated in volt)
Represents | voltage (Q25428) | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
Data type | Quantity | |||||||||
Domain | electrified stuff (note: this should be moved to the property statements) | |||||||||
Allowed units | volt (Q25250) | |||||||||
Example | According to this template:
3000 V DC (as qualifier of Florence–Rome railway (Q1158780)type of electrification (P930)overhead contact line (Q110701))
According to statements in the property:
When possible, data should only be stored as statementsVorab power line (Q2533447) → 220,000 volt 380,000 volt 25 kV AC railway electrification (Q1412243) → 25,000 volt Arduino/Genuino Zero (Q26225909) → 3.3 volt | |||||||||
Tracking: usage | Category:Pages using Wikidata property P2436 (Q120542753) | |||||||||
See also | frequency (P2144) | |||||||||
Lists | ||||||||||
Proposal discussion | Proposal discussion | |||||||||
Current uses |
|
[create Create a translatable help page (preferably in English) for this property to be included here]
Units: “volt (Q25250)”: value unit must be one of listed. (Help)
Exceptions are possible as rare values may exist. Exceptions can be specified using exception to constraint (P2303). List of violations of this constraint: Database reports/Constraint violations/P2436#Units
Allowed entity types are Wikibase item (Q29934200): the property may only be used on a certain entity type (Help)
Exceptions are possible as rare values may exist. Exceptions can be specified using exception to constraint (P2303). List of violations of this constraint: Database reports/Constraint violations/P2436#Entity types
Not qualifier only edit
There seems to be many uses of this property as main value:
SELECT ?item ?itemLabel ?voltage WHERE {
SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],en". }
OPTIONAL { ?item wdt:P2436 ?voltage. }
}
LIMIT 1000
In fact, there are about 600 uses of this property as main value, compared to only about 30 as qualifier:
SELECT DISTINCT ?item ?property ?propertyLabel ?asObject ?asObjectLabel
WHERE
{
?prop pq:P2436 ?asObject .
hint:Query hint:optimizer "None" .
?item ?p ?prop .
?property wikibase:claim ?p .
?property wikibase:statementProperty ?ps .
?prop ?ps ?value .
SERVICE wikibase:label { bd:serviceParam wikibase:language "en" }
}
ORDER BY ASC(?propertyLabel)
LIMIT 1000
So I'm removing the constraint that says this property should only be used as qualifier. Feel free to propose how to migrate the existing uses if you disagree... Deryck Chan (talk) 13:28, 30 June 2018 (UTC)
Removed minimum value constraint edit
There was a minimum value constraint of 0 V. I removed it because negative voltages (relative to ground (Q6501125)) are routinely used in some areas of electronics, e.g. the -5V rail of an ATX power supply. 73.202.12.249