1： 找小于最大的最大的
select max(Salary) from Employee where Salary<(select MAX(Salary) from Employee);
2. 排序
select Salary from Employee where Salary not in (select MAX(Salary)from Employee) order by Salary desc limit 1;
select ( select distinct Salary from Employee order by Salary Desc limit 1 offset 1 ) as SecondHeighestSalary;
找第n个数：
CREATE FUNCTION getNthHighestSalary(N INT) RETURNS INT
BEGIN
DECLARE M INT;
set N=N-1;
RETURN (
# Write your MySQL query statement below.
select Salary from Employee order by Salary desc limit 1 offset N
);
END
CREATE FUNCTION getNthHighestSalary(N INT) RETURNS INT
BEGIN
DECLARE M INT;
set N=N-1;
RETURN (
# Write your MySQL query statement below.
select distinct Salary from Employee order by Salary desc limit 1 offset N
);
END
不能在limit 里N-1， 因为limit里不计算
哈哈： distinct ：在表中可能包含重复值，返回唯一不同的值，
找第二大的数SQL-Second Highest Salary
原文：http://www.cnblogs.com/fanhaha/p/7257178.html