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..
1581. Customer Who Visited but Did Not Make Any Transactions table: Visits+-------------+---------+| Column Name | Type |+-------------+---------+| visit_id | int || customer_id | int |+-------------+---------+visit_id is the column with unique values for this table.This table contains information about the customers who visited the mall. Table: Transactions+----------------+-----..
1683. Invalid Tweets Table: Tweets+----------------+---------+| Column Name | Type |+----------------+---------+| tweet_id | int || content | varchar |+----------------+---------+tweet_id is the primary key (column with unique values) for this table.content consists of alphanumeric characters, '!', or ' ' and no other special characters.This table contains all the tweets i..
문제1.더보기 >> 출력 결과:>> 내 작성 쿼리문 (정답)SELECT COUNT(distinct business_entity_id) as customer_countFROM personWHERE email_promotion != 0 AND person_type = 'IN';>> 🔍 해설 쿼리 : 여러가지 풀이!!SELECTFROM personWHERE email_promotion IN (1, 2) AND person_type = 'IN' >>> WHERE 절 대체 가능:✅ email_promotion > 0✅ email_promotion BETWEEN 1 AND 2문제2.더보기🚨 아래 사진처럼 테이블 간의 관계도(?)를 (머리속에) 그려보면 이해하기가 수월해짐!! 이게 ERD, 엔티티 관계도 라..