해리문의 데이터_log

solvesql - 친구 수 집계하기👉 문제 바로가기(solvesql)-- 데이터베이스에 포함된 모든 사용자에 대해 각 사용자의 친구 수를 집계해 출력WITH tmp_t AS ( SELECT user_id, SUM(num_friends) as num_friends FROM (SELECT user_a_id as user_id, COUNT(DISTINCT user_b_id) as num_friends FROM edges GROUP BY user_a_id UNION ALL SELECT user_b_id as user_id, COUNT(DISTINCT user_a_id) as num_friends FROM edges GROUP BY user_b_id) GR..

HackerRank Intermediate - The PADS👉 문제 바로가기(HackerRank)-- 풀이1. 테이블 병합하여 한번에 출력SELECT col FROM ( SELECT CONCAT(NAME, '(', LEFT(Occupation,1), ')') AS col, 1 AS sort_order, NAME AS sort_value, NULL AS cnt, NULL AS occ FROM OCCUPATIONS UNION ALL SELECT CONCAT('There are a total of ', COUNT(*), ' ', LOWER(Occupation), 's.') AS col, ..