Coverage for ckanext/udc/graph/queries.py: 28%

1import logging 

2import ckan 

3import ckan.plugins.toolkit as tk 

4import ckan.plugins as plugins 

5 

6from datetime import datetime 

7from .sparql_client import SparqlClient 

8 

9log = logging.getLogger(__name__) 

10 

11 

12def get_client() -> SparqlClient: 

13 return plugins.get_plugin('udc').sparql_client 

14 

15 

16def get_uri_as_object_usage(object_uri): 

17 """Return the number of occurrence when the uri is used as an object.""" 

18 query = f""" 

19 select (count(?s) as ?cnt) where {{ 

20 ?s ?p <{object_uri}> . 

21 }} 

22 """ 

23 client = get_client() 

24 result = client.execute_sparql(query) 

25 

26 return int(result["results"]["bindings"][0]["cnt"]["value"]) 

27 

28def get_o_by_sp(s, p): 

29 query = f""" 

30 select ?o where {{ 

31 <{s}> <{p}> ?o . 

32 }} LIMIT 1""" 

33 client = get_client() 

34 result = client.execute_sparql(query) 

35 if len(result["results"]["bindings"]) > 0: 

36 return result["results"]["bindings"][0]["o"]["value"] 

37 return None 

38 

39def get_num_paths(uri_a: str, uri_b: str): 

40 """ 

41 Find the number of paths from 'uri_a' to 'uri_b'. 

42 https://graphdb.ontotext.com/documentation/10.2/graph-path-search.html 

43 """ 

44 query = f""" 

45 PREFIX path: <http://www.ontotext.com/path#> 

46 PREFIX xsd: <http://www.w3.org/2001/XMLSchema#> 

47 

48 SELECT ?pathIndex ?edgeIndex ?edge 

49 WHERE {{ 

50 SERVICE path:search {{ 

51 [] path:findPath path:allPaths ; 

52 path:sourceNode <{uri_a}> ; 

53 path:destinationNode <{uri_b}> ; 

54 path:pathIndex ?pathIndex; 

55 path:resultBindingIndex ?edgeIndex ; 

56 path:resultBinding ?edge ; 

57 }} 

58 }} 

59 """ 

60 client = get_client() 

61 result = client.execute_sparql(query) 

62 # print('num_paths=', len(result["results"]["bindings"]), uri_a, uri_b) 

63 # {pathIndex: {edgeIndex: str[]}}  

64 results = {} 

65 for row in result["results"]["bindings"]: 

66 pathIndex = row['pathIndex']['value'] 

67 edgeIndex = row['edgeIndex']['value'] 

68 edge = row['edge']['value'] 

69 # print(edge) 

70 s = edge['s']['value'] 

71 p = edge['p']['value'] 

72 o = edge['o']['value'] 

73 if not results.get(pathIndex): 

74 results[pathIndex] = {} 

75 

76 results[pathIndex][edgeIndex] = [s, p, o] 

77 

78 # Reformat it into {pathIndex: str[][]} 

79 for pathIndex in results: 

80 results[pathIndex] = [v for k, v in sorted(results[pathIndex].items())] 

81 

82 return results 

83