Sql dinamico me da fallo

tema enviado por eliancitomix en ORACLE
tema iniciado el 05/03/2007

Hola a todos me gustaria saber por que me falla este bloque de codigo anonimo:

DECLARE

CURSOR cursor_constraints

IS

SELECT 'ALTER TABLE '

|| table_name

|| ' DISABLE CONSTRAINT '

|| constraint_name

|| ' CASCADE;' AS instruccion

FROM dba_constraints

WHERE table_name IN

('tabla1', tabla2', 'tabla3')

AND owner = 'UnNombre';

fila_con cursor_constraints%ROWTYPE;

BEGIN

OPEN cursor_constraints;

FETCH cursor_constraints

INTO fila_con;

WHILE cursor_constraints%FOUND

LOOP

EXECUTE IMMEDIATE fila_con.instruccion;

FETCH cursor_constraints

INTO fila_con;

END LOOP;

CLOSE cursor_constraints;

END;

/

ERROR en línea 1:
ORA-00911: invalid character
ORA-06512: at line 23