전체 글
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MYSQL 정규표현식공부/PS ( SQL) 2022. 5. 15. 23:56
https://velog.io/@gillog/MySQL-REGEXPRegular-Expression%EC%A0%95%EA%B7%9C-%ED%91%9C%ED%98%84%EC%8B%9D [MySQL] REGEXP(Regular Expression(정규 표현식)) REGEXP는 LIKE를 이용한 검색과 달리 Regular Expression(정규 표현식)를 이용해 검색한다.REGEXP를 사용하면 SQL에서 정규표현식을 활용하여 기본 연산자보다 복잡한 문자열 조건을 걸어 데이터를 검색할 velog.io
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[HackerRank/Basic Select] Weather Observation Station 8공부/PS ( SQL) 2022. 5. 15. 23:55
https://www.hackerrank.com/challenges/weather-observation-station-8/problem Weather Observation Station 8 | HackerRank Query CITY names that start AND end with vowels. www.hackerrank.com 문제 풀이 SELECT DISTINCT CITY FROM STATION WHERE CITY REGEXP "^[aeiou]" AND CITY REGEXP "[aeiou]$" 정규표현식 사용 컬럼명 REGEXP "^[시작할 문자열]" AND 컬럼명 REGEXP "[끝나는 문자열]$"
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[HackerRank/Basic Select] Weather Observation Station 7공부/PS ( SQL) 2022. 5. 15. 23:21
https://www.hackerrank.com/challenges/weather-observation-station-7/problem Weather Observation Station 7 | HackerRank Query the list of CITY names ending with vowels (a, e, i, o, u) from STATION. www.hackerrank.com 문제 풀이 SELECT DISTINCT CITY FROM STATION WHERE CITY LIKE '%a' OR CITY LIKE '%e' OR CITY LIKE '%i' OR CITY LIKE '%o' OR CITY LIKE '%u'
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[HackerRank/Basic Select] Weather Observation Station 6공부/PS ( SQL) 2022. 5. 15. 23:18
https://www.hackerrank.com/challenges/weather-observation-station-6/problem Weather Observation Station 6 | HackerRank Query a list of CITY names beginning with vowels (a, e, i, o, u). www.hackerrank.com 문제 풀이 SELECT DISTINCT CITY FROM STATION WHERE CITY LIKE 'a%' OR CITY LIKE 'e%' OR CITY LIKE 'i%' OR CITY LIKE 'o%' OR CITY LIKE 'u%'
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[HackerRank/Basic Select] Weather Observation Station 5공부/PS ( SQL) 2022. 5. 15. 23:11
https://www.hackerrank.com/challenges/weather-observation-station-5/problem Weather Observation Station 5 | HackerRank Write a query to print the shortest and longest length city name along with the length of the city names. www.hackerrank.com 문제 풀이 SELECT CITY, LENGTH(CITY) FROM STATION ORDER BY LENGTH(CITY), CITY LIMIT 1; SELECT CITY, LENGTH(CITY) FROM STATION ORDER BY LENGTH(CITY) DESC, CITY ..
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[HackerRank/Basic Select] Weather Observation Station 4공부/PS ( SQL) 2022. 5. 15. 22:48
https://www.hackerrank.com/challenges/weather-observation-station-4/problem?isFullScreen=true Weather Observation Station 4 | HackerRank Find the number of duplicate CITY names in STATION. www.hackerrank.com 문제 풀이 SELECT COUNT(CITY) - COUNT(DISTINCT(CITY)) FROM STATION
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[C++] STL - map, set공부/C, C++ 2022. 5. 12. 17:33
STL container - 시퀀스 컨테이너 / 연관 컨테이너 시퀀스 컨테이너: vector, list, deque 등 순서대로 데이터를 보관할때 사용 연관 컨테이너: map, set 등 형태로 데이터를 보관할때 사용. 찾고자하는 데이터를 빠르게 찾을 때 사용. map, set key의 중복을 허용하지 않음 중복되는 key를 사용하는 경우에는 컨테이너 앞에 'multi'를 붙임. ex) multi_map, multi_set key 기준으로 데이터를 정렬하여 저장함 map Red-Black tree 자료구조를 가짐 형태로 데이터를 저장 key를 기준으로 오름차순 정렬함 map 선언 예시) #include map map1; set map과 비슷하지만 map과 달리 key만 저장함 key를 기준으로 오름차순 ..