q'! text-to-be-quoted !'

! is a signle character, called the quote delimiter. with the quote operator, apostrophes don't have to be dboule:

e.g.

select q'#Oracle's quote operator#' quote_test from dual;
QUOTE_TEST
--------------------------
Oracle's quote operator

it's very helpful and convenience to use the quote, particularly when you want to update or insert a very long and big sql.

e.g:

DECLARE
l_sql VARCHAR2(32767);
BEGIN
l_sql := q'!
select ********** very very long sql here
!';

UPDATE table_name
SET attribute = l_sql
WHERE condition;

COMMIT;

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