SparqlClient Class
The SparqlClient class provides a ROS service to explore ontologenius with SPARQL-like queries. More...
| Ros1 Package: | ontologenius |
| Ros2 Package: | ontopy |
Methods
Detailed Description
The SparqlClient class provides a ROS service to explore ontologenius with SPARQL-like queries.
The variables start with the symbol ? (e.g. ?my_var) and each triplet is separated by a dot.
Methods Documentation
__init__(self, name)
Constructs a sparql client.
Can be used in a multi-ontology mode by specifying the name of the ontology name(str). For classic use, name should be defined as ''.
call(self, query)
Basic query Examples
The general structure is always the same:
SELECT * // or ?x to get specific variables
WHERE {
// pattern
}
You can also add the DISTINCT keyword just after the SELECT to ensure unique results. The following blocks are examples of possible patterns.
Bedroom isA ?type
names: [type]
results:
- values: [Room]
Give to class of Bedroom.
?table isA Table
names: [table]
results:
- values: [Table2]
- values: [Table1]
Give all the tables.
Table1 isIn ?room
names: [room]
results:
- values: [Bedroom]
Give all the individuals for which the individual 'Table1' is in it.
?object isA Table. ?object isIn ?room
names: [object, room]
results:
- values: [Table2, LivingRoom]
- values: [Table1, Bedroom]
Give all the individuals that are tables and the room in which they are.
Query with negation
?object isA Table NOT EXISTS { ?object isIn LivingRoom }
names: [object]
results:
- values: [Table1]
Give all the individuals that are tables and not in the living room.