Complex query in SQL with a condition? Is it possible?

Question

MySQL

I write the following query (simplified here):

SELECT
            `name`,
            (SELECT `value` FROM `t` ORDER BY `value` DESC LIMIT 1,1) AS `second_value`,
FROM `t`;

That is, you need to get the second most value from the table `t` ordered by `value`. Sometimes this table has only one row and then SQL returns NULL, but you need to return (SELECT `value` FROM `t` ORDER BY `value` DESC LIMIT 0,1) - that is, the only value that is in the table.
Maybe I'm doing it all wrong, correct me if you can.

Answer 1

There is a function IFNULL , you can pass two subqueries to it.
True, the solution gives some kind of curvature.

Answer 2

SELECT `value`
    FROM (SELECT `value` FROM `t` ORDER BY `value` LIMIT 2) AS `t1`
    ORDER BY `value` DESC
    LIMIT 1