遇到一个新语法,记录在案
查询Employee 表中的第二高的salary,如果没有则返回null
mysql:ifnull
select
IFNULL(
(select DISTINCT Salary
from Employee
ORDER BY Salary DESC
limit 1 offset 1),NULL
) as SecondHightestSalary;
遇到一个新语法,记录在案
查询Employee 表中的第二高的salary,如果没有则返回null
mysql:ifnull
select
IFNULL(
(select DISTINCT Salary
from Employee
ORDER BY Salary DESC
limit 1 offset 1),NULL
) as SecondHightestSalary;