SPARQL/SERVICE - around and box

The service allows to search for items with coordinates located within a certain radius of the center or within a certain bounding box.

Most of the examples below use a map view by using #defaultView:Map at the top of the query. You may switch to table display to see the underlying data.

The property most commonly used for locations is coordinate location (P625).

Search around point

Example Airports within 100km from Berlin:

# Airports within 100km from Berlin
#defaultView:Map
SELECT ?place ?placeLabel ?location ?dist 
WHERE {
  # Berlin coordinates
  wd:Q64 wdt:P625 ?berlinLoc . 
  SERVICE wikibase:around { 
      ?place wdt:P625 ?location . 
      bd:serviceParam wikibase:center ?berlinLoc . 
      bd:serviceParam wikibase:radius "100" . 
      bd:serviceParam wikibase:distance ?dist.
  } 
  FILTER EXISTS {
    # Is an airport
    ?place wdt:P31/wdt:P279* wd:Q1248784 .
  }
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". } 
} 
ORDER BY ASC(?dist)

Try it!

The first line of the around service call must have format ?item predicate ?location, where the result of the search will bind ?item to items within the specified location and ?location to their coordinates. The parameters supported are:

Predicate	Meaning
wikibase:center	The point around which search is performed. Must be bound for search to work.
wikibase:radius	Distance from the center. Currently the distance is always in kilometers, other units are not supported yet.
wikibase:globe	The globe which is being searched. Optional, default it's Earth (wd:Q2).
wikibase:distance	The variable receiving distance information

Search within box

Example of box search Schools between San Jose, CA and Sacramento, CA:

# Schools between San Jose, CA and Sacramento, CA
#defaultView:Map
SELECT ?place ?placeLabel ?location 
WHERE {
  wd:Q16553 wdt:P625 ?SJloc.
  wd:Q18013 wdt:P625 ?SCloc.
  SERVICE wikibase:box {
      ?place wdt:P625 ?location.
      bd:serviceParam wikibase:cornerSouthWest ?SJloc.
      bd:serviceParam wikibase:cornerNorthEast ?SCloc.
  }
  ?place wdt:P31/wdt:P279* wd:Q3914.
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". } 
}

Try it!

Coordinates may be specified directly:

# Schools between San Jose, CA and Sacramento, CA
#same as previous
#defaultView:Map
SELECT ?place ?placeLabel ?location 
WHERE {
  SERVICE wikibase:box {
    ?place wdt:P625 ?location.
    bd:serviceParam wikibase:cornerWest "Point(-121.872777777 37.304166666)"^^geo:wktLiteral.
    bd:serviceParam wikibase:cornerEast "Point(-121.486111111 38.575277777)"^^geo:wktLiteral.
  }
  ?place wdt:P31/wdt:P279* wd:Q3914.
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". } 
}

Try it!

The first line of the box service call must have format ?item predicate ?location, where the result of the search will bind ?item to items within the specified location and ?location to their coordinates. The parameters supported are:

Predicate	Meaning
wikibase:cornerSouthWest	The south-west corner of the box.
wikibase:cornerNorthEast	The north-east corner of the box.
wikibase:cornerWest	The western corner of the box.
wikibase:cornerEast	The eastern corner of the box.
wikibase:globe	The globe which is being searched. Optional, default it's Earth (wd:Q2).

wikibase:cornerSouthWest and wikibase:cornerNorthEast should be used together, as well as wikibase:cornerWest and wikibase:cornerEast, and can not be mixed. If wikibase:cornerWest and wikibase:cornerEast predicates are used, then the points are assumed to be the coordinates of the diagonal of the box, and the corners are derived accordingly.

Distance function

The function geof:distance returns distance between two points, in kilometers. Example usage:

# Airports within 100km from Berlin
SELECT ?place ?placeLabel ?location ?dist 
WHERE {
  # Berlin coordinates
  wd:Q64 wdt:P625 ?berlinLoc. 
  SERVICE wikibase:around { 
      ?place wdt:P625 ?location. 
      bd:serviceParam wikibase:center ?berlinLoc. 
      bd:serviceParam wikibase:radius "100". 
  } 
  # Is an airport
  ?place wdt:P31/wdt:P279* wd:Q1248784.
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". } 
  BIND(geof:distance(?berlinLoc, ?location) as ?dist) 
} 
ORDER BY ?dist

Try it!

# Places around 0°,0° 
SELECT ?place ?placeLabel ?location ?dist
WHERE {
  SERVICE wikibase:around { 
      ?place wdt:P625 ?location. 
      bd:serviceParam wikibase:center "Point(0 0)"^^geo:wktLiteral.
      bd:serviceParam wikibase:radius "250". 
  } 
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
  BIND(geof:distance("Point(0 0)"^^geo:wktLiteral, ?location) as ?dist) 
} 
ORDER BY ?dist

Try it!

References

• Wikidata query service/User Manual