CTX_THES Package, 22 of 26

SYN

This function returns all synonyms of a phrase as recorded in the specified thesaurus.

Syntax 1: Table Result

CTX_THES.SYN(restab IN OUT NOCOPY EXP_TAB,
             phrase IN VARCHAR2, 
             tname  IN VARCHAR2 DEFAULT 'DEFAULT');

Syntax 2: String Result

CTX_THES.SYN(phrase IN VARCHAR2, 
             tname  IN VARCHAR2 DEFAULT 'DEFAULT') 
RETURN VARCHAR2;

restab

Optionally, specify the name of the expansion table to store the results. This table must be of type EXP_TAB which the system defines as follows:

type exp_rec is record (
    xrel varchar2(12),
    xlevel number,
    xphrase varchar2(256)
);
type exp_tab is table of exp_rec index by binary_integer;

See Also:
For more information about EXP_TAB, see "CTX_THES Result Tables and Data Types" in Appendix B, "Result Tables".

phrase

Specify phrase to lookup in thesaurus.

tname

Specify thesaurus name. If not specified, system default thesaurus is used.

Returns

This function returns a string of the form:

 {syn1}|{syn2}|{syn3} ...

Example

String Result

Consider a thesaurus named ANIMALS that has an entry for cat as follows:

CAT 
  SYN KITTY 
  SYN FELINE

To look-up the synonym for cat and obtain the result as a string, issue the following statements:

declare 
  synonyms varchar2(2000); 
begin 
  synonyms := ctx_thes.syn('CAT','ANIMALS'); 
  dbms_output.put_line('the synonym expansion for CAT is: '||synonyms); 
end;

This code produces the following output:

the synonym expansion for CAT is: {cat}|{kitty}|{feline}

Table Result

The following code looks up the synonyms for canine and obtains the results in a table. The contents of the table are printed to the standard output.

declare  
  xtab ctx_thes.exp_tab;  
begin 
  ctx_thes.syn(xtab, 'canine', 'my_thesaurus'); 
  for i in 1..xtab.count loop 
    dbms_output.put_line(lpad(' ', 2*xtab(i).xlevel) || 
    xtab(i).xrel || ' ' || xtab(i).xphrase); 
  end loop; 
end;