SEM_CONTAINS and rulebases

Question

Hi,
How do I perform a query using SEM_CONTAINS making use of rulebases?
Thanks.

Answer 1

The syntax is different. Searching for "a b c" using catsearch is the same as searching for "a AND b AND c" using contains. This is documented in the following section:
http://download.oracle.com/docs/cd/B28359_01/text.111/b28304/csql.htm#i997256
You can use a query template with context grammar to get the results that you would expect from a contains search. Please see the demonstration below.
SCOTT@orcl_11g> create table products_tbl(id number primary key, text varchar2(4000));
Table created.
SCOTT@orcl_11g> insert into products_tbl values(112,'Smith Bitter');
1 row created.
SCOTT@orcl_11g> insert into products_tbl values(113,'Bitter Smith');
1 row created.
SCOTT@orcl_11g> commit;
Commit complete.
SCOTT@orcl_11g> create index products_idx on products_tbl( text )
  2  indextype is ctxsys.context;
Index created.
SCOTT@orcl_11g> column text format a30
SCOTT@orcl_11g> select * from products_tbl where contains(text,'Bitter Smith',1) >0;
        ID TEXT
       113 Bitter Smith
SCOTT@orcl_11g> drop index products_idx;
Index dropped.
SCOTT@orcl_11g> create index products_idx on products_tbl( text )
  2  indextype is ctxsys.ctxcat;
Index created.
SCOTT@orcl_11g> select * from products_tbl where catsearch(text, 'Bitter Smith','')>0;
        ID TEXT
       112 Smith Bitter
       113 Bitter Smith
SCOTT@orcl_11g> select *
  2  from   products_tbl
  3  where  catsearch
  4             (text,
  5              '<query>
  6              <textquery grammer="CONTEXT" language="english">Bitter Smith
  7              </textquery>
  8            </query>','') > 0;
        ID TEXT
       113 Bitter Smith
SCOTT@orcl_11g>