列的sql max sub

Question

首先我做了：

CREATE TABLE Persons (
  id INTEGER not null,
  capital_loss INTEGER, 
  capital_gain INTEGER, 
  salary INTEGER,
  PRIMARY KEY ( id )
);

我想获得一行的id和薪水：

max(capital_gain-capital_loss) and salary =50

先谢谢

Answer 1

这个怎么样

select id, salary, max(capital_gain - capital_loss)
from Persons 
where salary = 50
group by id, salary 

Answer 2

记住你的条件（无论从所有最大行返回哪一行），以及你是否使用mysql：

SELECT id, salary FROM Persons
WHERE salary=50
ORDER BY (capital_gain - capital_loss) DESC LIMIT 1;