【leetcode】176. 第二高的薪水

題目：

答案：

1

# Write your MySQL query statement below  
select IFNULL((select Distinct Salary from Employee order by Salary DESC limit 1,1),null) as SecondHighestSalary 

2

# Write your MySQL query statement below  
select max(Salary) as SecondHighestSalary from Employee where Salary<(select max(Salary) from Employee) 

筆記：

LIMIT：

select * from Customer LIMIT 10;--檢索前10行數據，顯示1-10條數據
select * from Customer LIMIT 1,10;--檢索從第2行開始，累加10條id記錄，共顯示id爲2....11
select * from Customer limit 5,10;--檢索從第6行開始向前加10條數據，共顯示id爲6,7....15
select * from Customer limit 6,10;--檢索從第7行開始向前加10條記錄，顯示id爲7,8...16