Oracle PL/SQL/Large Objects/empty clob

Use function empty_clob to insert empty clob value

 
SQL>
SQL>
SQL> create table my_lob(
  2        id number,
  3        c clob )
  4      /
Table created.
SQL> insert into my_lob values ( 1, empty_clob() );
1 row created.
SQL>
SQL> select * from my_lob;
        ID C
---------- --------------------------------------------------------------------------------
         1
1 row selected.
SQL>
SQL> drop table my_lob;
Table dropped.
SQL> --