분류 전체보기(51)
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[LeetCode MySQL] 627. Swap Salary
627. Swap Salary Given a table salary, such as the one below, that has m=male and f=female values. Swap all f and m values (i.e., change all f values to m and vice versa) with a single update statement and no intermediate temp table. Note that you must write a single update statement, DO NOT write any select statement for this problem. Example: | id | name | sex | salary | |----|------|-----|---..
2021.01.19 -
[HackerRank MySQL] The Report
The Report You are given two tables: Students and Grades. Students contains three columns ID, Name and Marks. Grades contains the following data: Ketty gives Eve a task to generate a report containing three columns: Name, Grade and Mark. Ketty doesn't want the NAMES of those students who received a grade lower than 8. The report must be in descending order by grade -- i.e. higher grades are ente..
2021.01.19 -
[LeetCode MySQL] 177. Nth Highest Salary
177. Nth Highest Salary Write a SQL query to get the nth highest salary from the Employee table. +----+--------+ | Id | Salary | +----+--------+ | 1 | 100 | | 2 | 200 | | 3 | 300 | +----+--------+ For example, given the above Employee table, the nth highest salary where n = 2 is 200. If there is no nth highest salary, then the query should return null. +------------------------+ | getNthHighestS..
2021.01.19 -
[LeetCode MySQL] 185. Department Top Three Salaries
185. Department Top Three Salaries The Employee table holds all employees. Every employee has an Id, and there is also a column for the department Id. +----+-------+--------+--------------+ | Id | Name | Salary | DepartmentId | +----+-------+--------+--------------+ | 1 | Joe | 85000 | 1 | | 2 | Henry | 80000 | 2 | | 3 | Sam | 60000 | 2 | | 4 | Max | 90000 | 1 | | 5 | Janet | 69000 | 1 | | 6 | R..
2021.01.19 -
[LeetCode MySQL] 184. Department Highest Salary
184. Department Highest Salary The Employee table holds all employees. Every employee has an Id, a salary, and there is also a column for the department Id. +----+-------+--------+--------------+ | Id | Name | Salary | DepartmentId | +----+-------+--------+--------------+ | 1 | Joe | 70000 | 1 | | 2 | Jim | 90000 | 1 | | 3 | Henry | 80000 | 2 | | 4 | Sam | 60000 | 2 | | 5 | Max | 90000 | 1 | +--..
2021.01.19 -
[LeetCode MySQL] 180. Consecutive Numbers
180. Consecutive Numbers Table: Logs +-------------+---------+ | Column Name | Type | +-------------+---------+ | id | int | | num | varchar | +-------------+---------+ id is the primary key for this table. Write an SQL query to find all numbers that appear at least three times consecutively. Return the result table in any order. The query result format is in the following example: Logs table: +..
2021.01.19