Oracle CLOB can't insert beyond 4000 characters?

Question

How do I insert more than 4000 characters to a CLOB type column?

--create test table s
create table s
(
      a clob
);
insert into s values('>4000 char')

Results in an error:

ORA-01704:the string too long.

I want to insert a string of >4000 characters one time. How do I do it? Is it possible?

When I read the Oracle reference, CLOB can save max 4GB(Gigabyte)?

Answer 1

The maximum for one time insertion is 4000 characters (the maximum string literal in Oracle). However you can use the lob function dbms_lob.append() to append chunks of (maximum) 4000 characters to the clob:

CREATE TABLE don (x clob);


DECLARE 
 l_clob clob;
BEGIN
  FOR i IN 1..10
  LOOP
    INSERT INTO don (x) VALUES (empty_clob()) --Insert an "empty clob" (not insert null)
    RETURNING x INTO l_clob;

    -- Now we can append content to clob (create a 400,000 bytes clob)
    FOR i IN 1..100
    LOOP
      dbms_lob.append(l_clob, rpad ('*',4000,'*'));
      --dbms_lob.append(l_clob, 'string chunk to be inserted (maximum 4000 characters at a time)');
    END LOOP;
  END LOOP;
END;