[SQL/코드카타] 유저별 confirmed 의 비율 ( 평균이 바로 비율 )

문제 더보기Table: Signups+----------------+----------+| Column Name | Type |+----------------+----------+| user_id | int || time_stamp | datetime |+----------------+----------+user_id is the column of unique values for this table.Each row contains information about the signup time for the user with ID user_id. Table: Confirmations+----------------+----------+| Column Name | ..

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• · 2025. 11. 21.
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[SQL/코드카타] 직속 하위 직원이 5명 이상인 매니저 찾기

문제 더보기Table: Employee+-------------+---------+| Column Name | Type |+-------------+---------+| id | int || name | varchar || department | varchar || managerId | int |+-------------+---------+id is the primary key (column with unique values) for this table.Each row of this table indicates the name of an employee, their department, and the id of their manager.If manag..

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• · 2025. 11. 19.
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[SQL/코드카타] 모든 조합의 CROSS JOIN과 참여한 시험을 LEFT JOIN

문제 더보기Table: Students+---------------+---------+| Column Name | Type |+---------------+---------+| student_id | int || student_name | varchar |+---------------+---------+student_id is the primary key (column with unique values) for this table.Each row of this table contains the ID and the name of one student in the school. Table: Subjects+--------------+---------+| Column Name | Ty..

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• · 2025. 11. 18.
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[SQL/코드카타] WHERE 조건절과 NULL값 출력

문제 87번 더보기Table: Employee+-------------+---------+| Column Name | Type |+-------------+---------+| empId | int || name | varchar || supervisor | int || salary | int |+-------------+---------+empId is the column with unique values for this table.Each row of this table indicates the name and the ID of an employee in addition to their salary and the id of their man..

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• · 2025. 11. 17.
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[SQL/코드카타] Average Time of Process per Machine

문제Table: Activity더보기+----------------+---------+| Column Name | Type |+----------------+---------+| machine_id | int || process_id | int || activity_type | enum || timestamp | float |+----------------+---------+The table shows the user activities for a factory website.(machine_id, process_id, activity_type) is the primary key (combination of columns with unique v..

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• · 2025. 11. 14.
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[SQL/코드카타] 하루 전 보다 온도가 높은 데이터 값 찾기

전 행과 데이터 비교하기 197. Rising Temperature Table: Weather+---------------+---------+| Column Name | Type |+---------------+---------+| id | int || recordDate | date || temperature | int |+---------------+---------+id is the column with unique values for this table.There are no different rows with the same recordDate.This table contains information about the temperature..

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• · 2025. 10. 30.
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