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Function expressions

    1 Types of functions
       1.1 Built-in functions
       1.2 Custom functions
    2 Example
       2.1 Built-in function
       2.2 Custom function
    3 See also

The FunctionExpression represent function expressions used in SPARQL Requests.

Function expressions can appear in SELECT, ASK, BIND, FILTER, or COALESCE constructs.

Types of functions

There are two kinds of functions:

Built-in functions which are part of the SPARQL language
Custom functions which can be define in any namespace

Built-in functions

Built-in functions are created with one of the following constructors:

The supported built-in functions are:

The BOUND function
The IF function
The floor function
The ceil function
The round function
The abs function
The concat function
The strlen function
The substr function
The str function
The isNumeric function
The isLiteral function
The isIRI function
The isURI function
The IRI function
The IN function
The NOT IN function
The sameTerm function
The COUNT function
The SUM function
The coalesce function
The replace function
The contains function
The MAX function
The MIN function
The regex function
The EXISTS function
The NOT EXISTS function
The DATATYPE function
The AVG function
The strstarts function
The strends function
The UCASE function
The LCASE function
The STRBEFORE function
The STRAFTER function
The YEAR function
The MONTH function
The DAY function
The HOURS function
The MINUTES function
The SECONDS function
The NOW function
The TIMEZONE function
The TZ function
The isBlank function

Custom functions

Custom functions are created with one of the following constructors:

Example

Built-in function

For example:

   SELECT ?country (COUNT(?city) AS ?TotalCity)
   WHERE {  
      ?city ge:isLocatedIn ?country . 
      ?city rdf:type ge:City .
   } 
   GROUP BY ?country

Custom function

For example:

   SELECT ?zone ?distance
   WHERE {
      ?zone rdf:type sitac:TaskZone .
      ?zone sitac:Latitude ?lat .
      ?zone sitac:Longitude ?lon .
      BIND (geo:distance(?lat, ?lon) as ?distance)
   }