如何编写SPARQL查询获取指定距离内的DBpedia文化历史地点

I want to write a SPARQL query on DBPedia to find nearby cultural-historic sites based on given coordinates. I found an example query that retrieves locations within 20 km of New York City:

SELECT DISTINCT ?resource ?label ?location WHERE { 
  <http://dbpedia.org/resource/New_York_City> geo:geometry ?sourcegeo . 
  ?resource geo:geometry ?location ; 
            rdfs:label ?label . 
  FILTER( bif:st_intersects( ?location, ?sourcegeo, 20 ) ) . 
  FILTER( lang( ?label ) = "en" ) 
}

I need to modify this query so that it lists all cultural-historic sites within a custom distance (like the 20km in the example). How can I achieve this?

Answer #

Great question! Let's tweak your existing query to meet both requirements—customizable distance and filtering for cultural-historic sites—with clear, maintainable changes.

1. Add a Customizable Radius Parameter

First, replace the hardcoded 20 in the spatial filter with a variable you can set once at the top of the query. Using BIND makes it super easy to adjust the distance later:

BIND(20 AS ?radius) # Change this number to your desired km distance

Now you only need to edit one line to switch between 10km, 30km, or any other range.

2. Filter for Cultural-Historic Site Types

Your original query pulls all locations with geometry data, which includes parks, businesses, etc. To narrow it to cultural-historic sites, we'll add a triple that links ?resource to relevant DBPedia ontology classes. Common options are:

• dbo:CulturalHeritageSite (official cultural heritage listings)
• dbo:HistoricSite (historic locations of note)
• dbo:Monument (statues, memorials, and monuments)
• dbo:ArchaeologicalSite (archaeological digs or ruins)

Use a VALUES clause to include multiple types cleanly—this is more readable than chaining UNION statements.

Final Modified Query #

Here's the complete, flexible query that combines both changes:

SELECT DISTINCT ?resource ?label ?location WHERE {
  # Set your desired search radius (in kilometers) here
  BIND(20 AS ?radius)
  
  # Replace this with your target location's DBPedia resource
  <http://dbpedia.org/resource/New_York_City> geo:geometry ?sourcegeo .
  
  # Filter for cultural-historic site categories
  ?resource rdf:type ?siteType ;
            geo:geometry ?location ;
            rdfs:label ?label .
  
  VALUES ?siteType {
    dbo:CulturalHeritageSite
    dbo:HistoricSite
    dbo:Monument
    dbo:ArchaeologicalSite
  }
  
  # Spatial filter using our custom radius
  FILTER( bif:st_intersects( ?location, ?sourcegeo, ?radius ) )
  # Keep only English labels for readability
  FILTER( lang( ?label ) = "en" )
}

Bonus: Use Raw Coordinates Instead of a City Resource #

If you don't want to rely on a DBPedia city resource, you can input raw latitude/longitude directly using bif:st_point (note: the order is longitude first, then latitude):

SELECT DISTINCT ?resource ?label ?location WHERE {
  BIND(20 AS ?radius)
  # Input your coordinates here: bif:st_point(longitude, latitude)
  BIND(bif:st_point(-74.0060, 40.7128) AS ?sourcegeo) # NYC's coordinates
  
  ?resource rdf:type ?siteType ;
            geo:geometry ?location ;
            rdfs:label ?label .
  
  VALUES ?siteType {
    dbo:CulturalHeritageSite
    dbo:HistoricSite
    dbo:Monument
    dbo:ArchaeologicalSite
  }
  
  FILTER( bif:st_intersects( ?location, ?sourcegeo, ?radius ) )
  FILTER( lang( ?label ) = "en" )
}

Quick Tips #

• The bif: prefix is specific to DBPedia's BigData endpoint—don't remove it, as the spatial functions won't work without it.
• Keep DISTINCT to avoid duplicate results (some sites might be tagged with multiple heritage categories).
• Expand the VALUES ?siteType list if you want to include other relevant classes, like dbo:Museum or dbo:Castle.

内容的提问来源于stack exchange，提问作者outbeyond