Is it possible to use LONG columns in WHERE clause or ORDER BY?

Question

Is it possible to use LONG columns in WHERE clause or ORDER BY?

Answer 1

Hi,
LONG data type is deprecated, maybe could you change your column type to LOB ?
Nonetheless below is a workaround which may fit your needs if forced to use LONG.
It uses a function which returns you a CLOB. It allows you to use the converted "LONG" column in a WHERE clause.
Then if you want to order by you have to convert the CLOB to a VARCHAR using DBMS_LOB.SUBSTR.
SQL> CREATE TABLE my_table (id NUMBER, description LONG);
Table created.
SQL> INSERT INTO my_table VALUES (1, 'FIRST LONG');
1 row created.
SQL> INSERT INTO my_table VALUES (2, 'ANOTHER LONG');
1 row created.
SQL> COMMIT;
Commit complete.
SQL> CREATE TYPE my_type_row AS OBJECT (id INTEGER, description CLOB);
  2  /
Type created.
SQL> CREATE TYPE my_type_table AS TABLE OF my_type_row;
  2  /
Type created.
SQL> CREATE OR REPLACE FUNCTION get_my_long
  2     RETURN my_type_table
  3     PIPELINED
  4  AS
  5     v_tab   my_type_table := my_type_table ();
  6  BEGIN
  7    FOR cur IN (SELECT id, description FROM my_table)
  8  LOOP
  9        PIPE ROW (my_type_row (cur.id, cur.description));
10  END LOOP;
11  RETURN;
12  END;
13  /
Function created.
SQL> SELECT
  2     id,
  3     description
  4  FROM
  5     TABLE (get_my_long ())
  6  WHERE
  7     description LIKE '%LONG'
  8  ORDER BY
  9     DBMS_LOB.SUBSTR(description);
  ID DESCRIPTION
   2 ANOTHER LONG
   1 FIRST LONG
SQL> SELECT
  2     id,
  3     description
  4  FROM
  5     TABLE (get_my_long ())
  6  WHERE
  7     description LIKE 'FI%';
  ID DESCRIPTION
   1 FIRST LONG
SQL>Kind regards,
Ludovic