ror_coding

MySQL에선 select 구문의 alias를 group by 에서 쓸 수 있다 ! Question We define an employee's total earnings to be their monthly worked, and the maximum total earnings to be the maximum total earnings for any employee in the Employee table. Write a query to find the maximum total earnings for all employees as well as the total number of employees who have maximum total earnings. Then print these values as s..

삼각형이 되기 위한 세 변의 조건. Question Write a query identifying the type of each record in the TRIANGLES table using its three side lengths. Output one of the following statements for each record in the table:Equilateral: It's a triangle with sides of equal length.Isosceles: It's a triangle with sides of equal length.Scalene: It's a triangle with sides of differing lengths.Not A Triangle: The given va..

20 20이 self join하는 예외 케이스 나눠서 풀기 ! QuestionYou are given a table, Functions, containing two columns: X and Y.Two pairs (X1, Y1) and (X2, Y2) are said to be symmetric pairs if X1 = Y2 and X2 = Y1.Write a query to output all such symmetric pairs in ascending order by the value of X. List the rows such that X1 ≤ Y1.Sample InputSample Output20 2020 2122 23 Point 20 20이 하나만 있을 때 서로 self join해서 20 20 ..

WITH RECURSIVE (CTE) 로 Level 구하기 !!! 매우 중요! Question You are given a table, BST, containing two columns: N and P, where N represents the value of a node in Binary Tree, and P is the parent of N.Write a query to find the node type of Binary Tree ordered by the value of the node. Output one of the following for each node:Root: If node is root node.Leaf: If node is leaf node.Inner: If node is neith..

MySQL에서 Pivot 추출하는 방법! CASE-WHEN 을 사용한다. Question Pivot the Occupation column in OCCUPATIONS so that each Name is sorted alphabetically and displayed underneath its corresponding Occupation. The output should consist of four columns (Doctor, Professor, Singer, and Actor) in that specific order, with their respective names listed alphabetically under each column.Note: Print NULL when there are no..

eval을 이용해서 연산 ! Question 수식에 연산자가 3개 주어졌으므로 가능한 연산자 우선순위 조합은 3! = 6가지이며, 그 중 + > - > * 로 연산자 우선순위를 정한다면 결괏값은 22,000원이 됩니다. 반면에 * > + > - 로 연산자 우선순위를 정한다면 수식의 결괏값은 -60,420 이지만, 규칙에 따라 우승 시 상금은 절댓값인 60,420원이 됩니다.참가자에게 주어진 연산 수식이 담긴 문자열 expression이 매개변수로 주어질 때, 우승 시 받을 수 있는 가장 큰 상금 금액을 return 하도록 solution 함수를 완성해주세요.[제한사항]expression은 길이가 3 이상 100 이하인 문자열입니다.expression은 공백문자, 괄호문자 없이 오로지 숫자와 3가지의 연산..