What are the advantages of SPARQL?
- SPARQL can fetch results/data from structured and semi-structured data.
- SPARQL can handle complex joins and relationships
- SPARQL can help to find the data by running queries of unknown relationships.
- SPARQL can transform RDF data into different vocabulries.
What is mean by RDF triples?
RDF triples are
- Subject
- Predicate
- Object
What are literals?
Literal is the lexical representation of values such as numbers and dates.
A literal can be the object but it can’t be subject or predicate.
Representation of literals = Representation of URI
| SELECT * WHERE{ ?S ?P ?O } limit 10 |
Example:
| PREFIX foaf: <http://xmlns.com/foaf/0.1/> SELECT ?name WHERE { ?person a foaf:Person. ?person foaf:name ?name } LIMIT 10 |
Note: It will show the name of from the DBpedia database. Output can be like this;
Output:
| name |
| “Akram”@en |
| “Ali”@en |
| “Azhar:@en |
Explanation:
Akram is the name of the person and en indicates that Akram name is a word of English languages.
Example 2:
| PREFIX foaf: <http://xmlns.com/foaf/0.1/> SELECT ?name ?age WHERE { ?person a foaf:Person; foaf:name ?name. OPTIONAL {?person foaf:age ?age} } |
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