Format

SEM_APIS.ESCAPE_CLOB_VALUE(
     val           IN  CLOB CHARACTER SET ANY_CS, 
     start_offset  IN NUMBER   DEFAULT 1, 
     end_offset    IN NUMBER   DEFAULT 0, 
     utf_encode    IN NUMBER   DEFAULT 1, 
     include_start IN NUMBER   DEFAULT 0,
     options       IN VARCHAR2 DEFAULT NULL,
     max_vc_len    IN NUMBER   DEFAULT 4000
     ) RETURN VARCHAR2 CHARACTER SET val%CHARSET;

Description

Returns the input CLOB value with special characters and non-ASCII characters escaped as specified by the W3C N-Triples format (http://www.w3.org/TR/rdf-testcases/#ntriples).

Parameters

val

The CLOB text to escape.

start_offset

The offset in val from which to start character escaping. The default (1) causes escaping to start at the first character of val.

end_offset

The offset in val from which to end character escaping. The default (0) causes escaping to continue through the end of val.

utf_encode

Set to 1 (the default) if non-ASCII characters and non-printable ASCII characters other than chr(8), chr(9), chr(10), chr(12), and chr(13) should be escaped. Otherwise, such characters will not be escaped.

include_start

Set to 1 if the characters in val from 1 to start_offset should be prefixed (prepended) to the return value. Otherwise, no such characters will be prefixed to the return value.

options

Reserved for future use.

max_vc_len

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

Usage Notes

For information about using the DO_UNESCAPE keyword in the options parameter of the SEM_MATCH table function, see Using the SEM_MATCH Table Function to Query RDF Data.

Examples

The following example escapes an input character string containing TAB and NEWLINE characters.

SELECT SEM_APIS.ESCAPE_CLOB_VALUE('abc' || chr(9) || 'def' || chr(10) || 'hij')
  FROM DUAL;