YSY의 데이터분석 블로그

목적 파이썬으로 데이터를 MYSQL의 DB에 적재하는 여러가지 방법을 알아봅니다. 데이터를 한번에 밀어넣는 방법과, 데이터를 업데이트 시켜주는 upsert 방법을 소개합니다 활용데이터 캐글의 bike 데이터를 활용 https://www.kaggle.com/c/bike-sharing-demand/data?select=train.csv 사전 작업 1: MYSQL WORKBENCH DB 연결 workbench에서 local DB를 연결합니다 connection name를 지정합니다 hostname : 로컬로 연결하려면 로컬 ip인 "127.0.0.1"(자동입력 되어있음), AWS RDS로 연결하려면 RDS의 hostname을 입력합니다 username : 기본은 "root" 입니다 password : "Sto..

www.hackerrank.com/challenges/15-days-of-learning-sql/problem 15 Days of Learning SQL | HackerRank find users who submitted a query every day. www.hackerrank.com Julia conducted a days of learning SQL contest. The start date of the contest was March 01, 2016 and the end date was March 15, 2016. Write a query to print total number of unique hackers who made at least submission each day (starting ..

Samantha interviews many candidates from different colleges using coding challenges and contests. Write a query to print the contest_id, hacker_id, name, and the sums of total_submissions, total_accepted_submissions, total_views, and total_unique_views for each contest sorted by contest_id. Exclude the contest from the result if all four sums are 0. Note: A specific contest can be used to screen..

www.hackerrank.com/challenges/symmetric-pairs/problem Symmetric Pairs | HackerRank Write a query to output all symmetric pairs in ascending order by the value of X. www.hackerrank.com You 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 ascendin..

www.hackerrank.com/challenges/placements/problem Placements | HackerRank Write a query to output the names of those students whose best friends got offered a higher salary than them. www.hackerrank.com You are given three tables: Students, Friends and Packages. Students contains two columns: ID and Name. Friends contains two columns: ID and Friend_ID (ID of the ONLY best friend). Packages contai..

www.hackerrank.com/challenges/sql-projects/problem SQL Project Planning | HackerRank Write a query to output the start and end dates of projects listed by the number of days it took to complete the project in ascending order. www.hackerrank.com You are given a table, Projects, containing three columns: Task_ID, Start_Date and End_Date. It is guaranteed that the difference between the End_Date an..

www.hackerrank.com/challenges/contest-leaderboard/problem Contest Leaderboard | HackerRank Generate the contest leaderboard. www.hackerrank.com You did such a great job helping Julia with her last coding contest challenge that she wants you to work on this one, too! The total score of a hacker is the sum of their maximum scores for all of the challenges. Write a query to print the hacker_id, nam..

www.hackerrank.com/challenges/challenges/problem Challenges | HackerRank Print the total number of challenges created by hackers. www.hackerrank.com Julia asked her students to create some coding challenges. Write a query to print the hacker_id, name, and the total number of challenges created by each student. Sort your results by the total number of challenges in descending order. If more than ..