You'll have to assign the value to a variable & use the variable to insert the data
DECLARE v_long_text CLOB; BEGIN v_long_text := 'your long string of text';
INSERT INTO table VALUES (1, v_long_text); END; To make it clear: there are limits set to character strings:
4000 bytes in SQL 32k in PLSQL
If you want to go above this, you'll have to use bind variables.