Format

SEM_APIS.RES2VID(
     vTab       IN VARCHAR2, 
     uri        IN VARCHAR2, 
     lt         IN VARCHAR2 DEFAULT NULL, 
     lang       IN VARCHAR2 DEFAULT NULL, 
     lval       IN CLOB DEFAULT NULL,
     vtyp       IN VARCHAR2 DEFAULT NULL,
     max_vc_len IN NUMBER DEFAULT 4000
     ) RETURN NUMBER;

Description

Returns the VALUE_ID for the canonical version of an RDF term, or NULL if the term does not exist in the values table.

Parameters

vTab

Values table to query for the VALUE_ID value. (Usually RDF_VALUE$)

uri

Prefix value of the RDF term.

lt

Data type URI of a types literal to look up. Do not include the enclosing angle brackets (‘<’ and ‘>’).

lang

Language tag of a language tagged literal to look up.

lval

The plain literal portion of a long literal to look up.

vtyp

The type of value:

• PL: Plain literal
• TL: Typed literal
• UR: URI/IRI
• BN: Blank node
• PL@ language: Tagged literal

The value type is determined automatically if this parameter is NULL.

max_vc_len

The maximum allowed length of a VARCHAR RDF term: 32767 or 4000 (the default).

Usage Notes

For information about the components of an RDF term stored in the RDF_VALUE$ table, see RDF Metadata Tables and Views..

Examples

The following example returns VALUE_ID values for the canonical versions of RDF terms. Comments before each SQL statement describe the purpose of the statement.

-- Look up the VALUE_ID for the RDF term <http://www.example.com/a>.
SELECT  sem_apis.res2vid('RDF_VALUE$','<http://www.example.com/a>') FROM DUAL;

-- Look up the VALUE_ID for the RDF term "abc".
SELECT sem_apis.res2vid('RDF_VALUE$','"abc"') FROM DUAL;

-- Look up the VALUE_ID for the RDF term "10"^^<http://www.w3.org/2001/XMLSchema#decimal>.
SELECT sem_apis.res2vid('RDF_VALUE$','"10"','http://www.w3.org/2001/XMLSchema#decimal') FROM DUAL;

-- Look up the VALUE_ID for the RDF term "abc"@en.
SELECT sem_apis.res2vid('RDF_VALUE$','"abc"',lang=>'en') FROM DUAL;

-- Look up the VALUE_ID for the long literal RDF term '"a CLOB literal"'.
SELECT sem_apis.res2vid('RDF_VALUE$',null,lval=>'"a CLOB literal"') FROM DUAL;