design.md

Design of mlsqlhttp

Select query syntax

SELECT [field list|*] FROM [triples|blank for documents].[RDF Type|collection]
WHERE [predicate|element] [=|<|>|<=|>=] LIMIT [start,]length

Examples

SELECT * FROM temperatures WHERE city='Derby'

Generates

cts:search(fn:collection(temperatures),
  cts:element-value-query(xs:QName("city"),"Derby")
)

Returns

uri	city	temperature	month
/temperatures/1	Derby	12	Jun
/temperatures/2	Derby	14	Apr

SELECT AVG(temp) FROM temperatures WHERE month='Jun'

Generates

TODO

Returns

AVG(temp)
10

SELECT * from "triples.<http://marklogic.com/semantics/Person>"
WHERE "<http://marklogic.com/semantics/Person/name>" = "Adam Fowler"

Generates

sem:sparql('
  SELECT ?subject ?predicate ?object GRAPH ?graph WHERE {
    ?subject a <http://marklogic.com/semantics/Person> .
    ?subject <http://marklogic.com/semantics/Person/name> "Adam Fowler" .
    ?subject ?predicate ?object .
  }
')

Returns

uri	subject	graph	http://marklogic.com/semantics/Person/name	etc
/triples/123456	http://marklogic.com/semantics/Person#AdamFowler	default	Adam Fowler	etc

SELECT subject,<http://marklogic.com/semantics/Person/age>
FROM "triples.<http://marklogic.com/semantics/Person>"
WHERE "<http://marklogic.com/semantics/Person/name>" = "Adam Fowler"

Generates

sem:sparql('
  SELECT ?subject ?predicate ?object GRAPH ?graph WHERE {
    ?subject a <http://marklogic.com/semantics/Person> .
    ?subject <http://marklogic.com/semantics/Person/name> "Adam Fowler" .
    ?subject ?predicate ?object .
    FILTER (?predicate = (<http://marklogic.com/semantics/Person/age>) ) .
  }
')

Returns

uri	subject	graph	http://marklogic.com/semantics/Person/age
/triples/123456	http://marklogic.com/semantics/Person#AdamFowler	default	33