How to compare two columns of a table with comma separated value that are not in same order?

Question

Have a table with two columns having comma separated value not in same order, so i want to simply check the columns are equal or not;

column1 | column2
a,b,c   = b,c,a      is valid
a,b,c   = a,b        is not valid
b,c,a   = a,b,c      is valid
a,b,c   = NULL       is not valid

CREATE TABLE Books
(`id` int, `columnfirst` varchar(500), `columnsecond` varchar(500));

INSERT INTO Books
(`id`, `columnfirst`, `columnsecond`)
VALUES
(1, 'a,b,c', 'b,a,c'),
(2, 'b,c,a', 'a,b'),
(3, 'a,b,c', 'a,c,b'),
(4, 'a,b,c', 'a,b,c'),
(5, 'a,b,c', NULL),
(6, 'a,b', NULL);