LeetCodeデータベース177. N番目に高い給与

177. N番目に高い給与

CREATE FUNCTION getNthHighestSalary(N INT) RETURNS INT
BEGIN
  SET N = N - 1; # 改变N的值
  RETURN (
      SELECT IFNULL( # 找不到返回NULL
          (SELECT DISTINCT Salary FROM Employee # 去重
          ORDER BY Salary DESC  # 降序
          LIMIT N,1) # 返回从第N行开始的1行数据
          ,NULL
      )
  );
END