문제 입력 코드SELECT sell_date, COUNT(DISTINCT(product)) AS num_sold, GROUP_CONCAT(DISTINCT(product)) AS productsFROM ActivitiesGROUP BY sell_dateORDER BY sell_dateSELECT sell_date, COUNT(DISTINCT(product)) AS num_sold, GROUP_CONCAT(DISTINCT(product) ORDER BY product ASC SEPARATOR ',') AS productsFROM ActivitiesGROUP BY sell_dateORDE..
문제 입력 코드1. SELECT ( SELECT DISTINCT Salary FROM Employee ORDER BY salary DESC LIMIT 1 OFFSET 1) AS SecondHighestSalary 2. SELECT DISTINCT MAX(salary) AS SecondHighestSalary FROM EmployeeWHERE salary 코드 설명#SELECT #DISTINCT #ORDER BY #DESC #LIMIT #OFFSET #MAX 문제 출처https://leetcode.com/problems/second-highest-salary/description/?envType=study-plan-v2&envId=top-sql-50
문제 입력 코드DELETE p1FROM person AS p1, person AS p2WHERE p1.email = p2.email AND p1.id > p2.idDELETE p1FROM person AS p1JOIN person AS p2ON p1.email = p2.emailWHERE p1.email = p2.email AND p1.id > p2.id 코드 설명#DELETE #JOIN #ON #WHERE 문제 출처https://leetcode.com/problems/delete-duplicate-emails/description/?envType=study-plan-v2&envId=top-sql-50
문제 입력 코드1. SELECT *FROM PatientsWHERE conditions LIKE 'DIAB1%' OR conditions LIKE '% DIAB1%'; 2. REGEXPSELECT *FROM PatientsWHERE conditions REGEXP '\\bDIAB1' 코드 설명#SELECT #WHERE #LIKE #% #REGEXP 문제 출처https://leetcode.com/problems/patients-with-a-condition/description/?envType=study-plan-v2&envId=top-sql-50
문제 입력 코드SELECT user_id, CONCAT(UPPER(LEFT(name, 1)), LCASE(SUBSTRING(name, 2))) AS nameFROM UsersORDER BY user_idSELECT user_id, CONCAT(UPPER(SUBSTRING(name, 1, 1)), LOWER(SUBSTRING(name, 2))) AS nameFROM UsersORDER BY user_idSELECT user_id, CONCAT(UPPER(SUBSTR(name, 1, 1)), LOWER(RIGHT(name, LENGTH(name)-1))) AS nameFROM UsersORDER BY user_id 코드 설명#SELECT #CONCAT #UPPER ..
문제 입력 코드1. SUBQUERYSELECT d.name AS Department, e.name AS Employee, e.salary AS SalaryFROM Employee AS eJOIN Department AS dON e.departmentId = d.idWHERE 3 > (SELECT COUNT(DISTINCT e2.salary) FROM Employee AS e2 WHERE e2.salary > e.salary AND e.departmentId = e2.departmentId) 2. WINDOW 함수 - DENSE_RANK()SELECT Department, Employee, SalaryFROM (SELECT d.name AS D..