Steps for Creating a Classification Application

The following example shows how to classify documents by defining simple categories, creating a CTXRULE index, and using MATCHES, using the CTXAPP role user myuser.

Connect As the Appropriate User
Connect as the CTXAPP role user myuser:
```
CONNECT myuser;
```

Create the Rule Table

We must create a rule table and populate it with query rules. In this example, we create a table called queries. Each row defines a category with an ID, and a rule which is a query string:

CREATE TABLE queries (
      query_id      NUMBER,
      query_string  VARCHAR2(80)
    );

    INSERT INTO queries VALUES (1, 'oracle');
    INSERT INTO queries VALUES (2, 'larry or ellison');
    INSERT INTO queries VALUES (3, 'oracle and text');
    INSERT INTO queries VALUES (4, 'market share');

Create Your CTXRULE Index

Create a CTXRULE index as follows:

CREATE INDEX queryx ON queries(query_string) INDEXTYPE IS CTXSYS.CTXRULE;

Classify with MATCHES

Use the MATCHES operator in the WHERE clause of a SELECT statement to match documents to queries and hence classify.

    COLUMN query_string FORMAT a35;
    SELECT query_id,query_string FROM queries
     WHERE MATCHES(query_string, 
                   'Oracle announced that its market share in databases 
                    increased over the last year.')>0;

  QUERY_ID QUERY_STRING                                                         
---------- -----------------------------------                                  
         1 oracle                                                               
         4 market share

As shown, the document string matches categories 1 and 4. With this classification you can perform an action, such as writing the document to a specific table or e-mailing a user.