レビューしている時に touchメソッド使って current_sign_in_atとかを力技で更新をしているのをみてもっと良い方法がないかと調べて見つけたのでメモに残す。 結論としては Devise::Models::Trackableモジュールの #update_track_fields!を使えば良い。 リポ…

問題 https://leetcode.com/problems/nth-highest-salary/ 解いた CREATE FUNCTION getNthHighestSalary(N INT) RETURNS INT BEGIN RETURN ( # Write your MySQL query statement below. SELECT DISTINCT Salary FROM (SELECT DENSE_RANK() OVER(ORDER BY Sa…

問題 https://leetcode.com/problems/implement-strstr/ 解いた # @param {String} haystack # @param {String} needle # @return {Integer} def str_str(haystack, needle) return -1 unless haystack.include? needle haystack.index(needle) end 結果

問題 leetcode.com 解いた SELECT Department, Employee, Salary FROM ( SELECT ( SELECT DISTINCT Salary FROM ( SELECT DENSE_RANK() OVER (ORDER BY Salary DESC) AS 'rank', Salary FROM Employee WHERE Employee.departmentId = DD.id) E WHERE E.rank …

問題 https://leetcode.com/problems/department-highest-salary/ 解いた SELECT EED.name AS 'Department', Employee.name AS 'Employee', Employee.salary AS 'Salary' FROM ( SELECT EE.Max, Department.name FROM ( SELECT MAX(salary) AS Max, departme…

問題 https://leetcode.com/problems/merge-two-sorted-lists/ 解いてみた # Definition for singly-linked list. # class ListNode # attr_accessor :val, :next # def initialize(val = 0, _next = nil) # @val = val # @next = _next # end # end # @para…

問題 https://leetcode.com/problems/consecutive-numbers/ 解いた SELECT L.num AS 'ConsecutiveNums' FROM Logs L, Logs LL, Logs LLL WHERE L.id = LL.id - 1 AND LL.id = LLL.id - 1 AND L.num = LL.num && LL.num = LLL.num GROUP BY L.num; 結果

問題 https://leetcode.com/problems/delete-duplicate-emails/ 解いた DELETE P FROM Person AS P, Person AS PP WHERE P.email = PP.email AND P.ID > PP.id; 結果