Select LONG column into CLOB variable

Question

Hi all,
I am trying retrieve the data present in a LONG column into a CLOB variable.
However I am getting an error, pls let me know how I can resolve it.
DECLARE
v_text CLOB;
BEGIN
SELECT TO_LOB(trigger_body)
INTO v_text
FROM
user_triggers
WHERE
ROWNUM <= 1;
END;
ERROR at line 8:
ORA-06550: line 8, column 20:
PL/SQL: ORA-00932: inconsistent datatypes: expected NUMBER got LONG
ORA-06550: line 8, column 5:
PL/SQL: SQL Statement ignored
Let me know if there is an alternate to this. I would like to get the data present in the LONG column into a variable.
The reason why I am not retrieving the LONG column into LONG variable is stated below (from Oracle Website):
You can insert any LONG value into a LONG database column because the maximum width of a LONG column is 2**31 bytes.
However, you cannot retrieve a value longer than 32760 bytes from a LONG column into a LONG variable.
Thanks and Regards,
Somu

Answer 1

There are couple of things I did (listed in order):
1) Create Global Temporary Table containing a CLOB column
2) Select LONG column and convert to CLOB by using TO_LOB and insert into Global Temporary Table containing a CLOB column
2) Select from this Global Temporary Table (which already contains data in CLOB) and assign it to a CLOB variable.
This is done because you can not directly use TO_LOB in a select statement to assign the value to a CLOB variable.
Stated below is an example:
-- Create Temporary Table
CREATE GLOBAL TEMPORARY TABLE glb_tmp_table_lob(
time TIMESTAMP WITH LOCAL TIME ZONE,
text CLOB
ON COMMIT DELETE ROWS;
-- PL/SQL Block to Execute
DECLARE
v_clob CLOB;
BEGIN
-- Insert into Temporary Table by converting LONG into CLOB
INSERT INTO glb_tmp_table_lob (
time ,
text
SELECT
sysdate ,
TO_LOB(dv.text)
FROM
dba_views dv
WHERE
ROWNUM <= 1
-- Select from the Temporary table into the variable
SELECT
gt.text
INTO
v_clob
FROM
glb_tmp_table_lob gt;
COMMIT;
-- Now you can use the CLOB variable as per your needs.
END;
/