TIL(Today I Learned)65일차(24.02.12)

심화 프로젝트

2024.02.12 - [데이터 분석 공부/프로젝트] - 심화프로젝트 7일차(시간별/요일별 사용자수 히트맵)(24.02.12)

심화프로젝트 7일차(시간별/요일별 사용자수 히트맵)(24.02.12)

 

SQL, PYTHON 예제 복습

1. SQL

2356. Number of Unique Subjects Taught by Each Teacher

https://leetcode.com/problems/number-of-unique-subjects-taught-by-each-teacher/

SELECT TEACHER_ID, COUNT(DISTINCT SUBJECT_ID) CNT
FROM TEACHER
GROUP BY TEACHER_ID

 

1141. User Activity for the Past 30 Days I

https://leetcode.com/problems/user-activity-for-the-past-30-days-i/

SELECT ACTIVITY_DATE DAY, COUNT(DISTINCT USER_ID) ACTIVE_USERS
FROM ACTIVITY
WHERE DATEDIFF('2019-07-27', ACTIVITY_DATE) + 1 <= 30 AND ACTIVITY_DATE <= '2019-07-27'
GROUP BY ACTIVITY_DATE

 

2. PYTHON

● 없는 숫자 더하기

https://school.programmers.co.kr/learn/courses/30/lessons/86051

def solution(numbers):
    answer = 0
    all_num = [1,2,3,4,5,6,7,8,9,0]
    for i in all_num:
        if i in numbers:
            pass
        else:
            answer+=i
    return answer

 

● 제일 작은 수 제거하기

https://school.programmers.co.kr/learn/courses/30/lessons/12935

def solution(arr):
    v = sorted(arr)
    v2 = v[0]
    arr.remove(v2)
    if len(arr) != 0:
        return arr
    else:
        arr.append(-1)
        return arr

 

SQLD(3주차-Entity)