PL/SQL CONSTANT declarations

DECLARE

  cDate  VARCHAR2(10) := '2011-10-30';

BEGIN

  NULL;

END;

/

DECLARE

    ->   cDate CONSTANT VARCHAR2(10) := '2011-10-30';

    -> BEGIN

    ->   NULL;

    -> END;

    -> /

ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'VARCHAR2(10) := '2011-10-30';

BEGIN

  NULL;

END' at line 2