--TO_CLOB

--Example 1
SELECT first_name, TO_CLOB(first_name) AS clob_value
FROM student
WHERE student_id = 1;

--Example 2
CREATE TABLE datatype_test (
nclob_column NCLOB
);

INSERT INTO datatype_test (nclob_column)
VALUES ('This is ä tëst');

SELECT nclob_column, TO_CLOB(nclob_column) AS clobvalue
FROM datatype_test;

http://www.databasestar.com/oracle-to_clob/

A few examples of the TO_CLOB function.

Oracle TO_CLOB Function

sql, Oracle

SQL