How to find second highest salary in MySQL

if you have MySQL table like below image

if you want to fetch second highest salary of employee following query will be useful for you.
select sal from emp group by sal order by sal desc Limit 1,1

your output will be like below image

if you want to fetch all employee which have second highest salary following query will be useful for you.
select * from emp where sal=(select sal from emp group by sal order by sal desc Limit 1,1)

your output will be like below image

One more query
SELECT * FROM  `users` WHERE  `id` = ( SELECT MAX( id ) -1 FROM  `users` )

SELECT * FROM  `users` WHERE  `id` < ( SELECT MAX( id ) -1 FROM  `users` ) ORDER BY id DESC LIMIT 1