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1 : N의 관계인 테이블 A와 B를 JOIN 할 때, 테이블 B의 데이터는 한개만 가져오고 싶을 때, TABLE_A ( IDX INT, NAME VARCHAR ) TABLE_B ( IDX INT, COUNT INT, SUBJECT VARCHAR ) TABLE_A IDX NAME 1 김철수 2 나영희 3 박소영 TABLE_B IDX COUNT SUBJECT 1 1 국어 1 1 영어 2 5 도덕 3 4 체육 일반적으로 JOIN을 걸게되면 SELECT A.IDX, NAME,COUNT,SUBJECT FROM TABLE_A AS A LEFT JOIN TABLE_B AS B ON A.IDX = B.IDX IDX NAME COUNT SUBJECT 1 김철수 1 국어 1 김철수 1 영어 2 나영희 5 도덕 3 박소영..

*작업환경 - Delphi 10.3 - MSSQL - FastReport 6.0 *사용 컴포넌트 - frxReport - frxDBDataset - AdoQuery - AdoTable - DataSource - AdoConnection : 위 컴포넌트들을 동적으로 생성해도 상관없음! 예시 ) 개발팀 팀원별 2020년 잔여 연차 리스트 뽑아보자! 1. 필요한 데이터 확인 - 잔여 연차 소모 독려를 위하여 개발팀 팀원들의 2020년 잔여 연차리스트가 필요 : 사원별 잔여 연차 리스트 테이블, 사원 정보 테이블(편의상 정규화 X) - 각 사원들은 고유한 사번이 존재 [사원 정보] - Master 사번 직책 이름 1234 팀장 김팀장 5678 과장 송과장 91011 대리 박대리 [사원별 잔여 연차 리스트] - ..

www.hackerrank.com/domains/sql Amber's conglomerate corporation just acquired some new companies. Each of the companies follows this hierarchy: Given the table schemas below, write a query to print the company_code, founder name, total number of lead managers, total number of senior managers, total number of managers, and total number of employees. Order your output by ascending company_code. No..

www.hackerrank.com/domains/sql Pivot the Occupation column in OCCUPATIONS so that each Name is sorted alphabetically and displayed underneath its corresponding Occupation. The output column headers should be Doctor, Professor, Singer, and Actor, respectively. Note: Print NULL when there are no more names corresponding to an occupation. Input Format The OCCUPATIONS table is described as follows: ..

www.hackerrank.com/domains/sql Query the two cities in STATION with the shortest and longest CITY names, as well as their respective lengths (i.e.: number of characters in the name). If there is more than one smallest or largest city, choose the one that comes first when ordered alphabetically. The STATION table is described as follows: where LAT_N is the northern latitude and LONG_W is the west..

www.hackerrank.com/domains/sql Find the difference between the total number of CITY entries in the table and the number of distinct CITY entries in the table. The STATION table is described as follows: where LAT_N is the northern latitude and LONG_W is the western longitude. For example, if there are three records in the table with CITY values 'New York', 'New York', 'Bengalaru', there are 2 dif..

www.hackerrank.com/domains/sql Query a list of CITY names from STATION for cities that have an even ID number. Print the results in any order, but exclude duplicates from the answer. The STATION table is described as follows: where LAT_N is the northern latitude and LONG_W is the western longitude. 짧은 영어실력으로 번역하자면.. STATION 테이블의 CITY 필드를 추출해 내는 것이 목표이고, 조건은 ID가 EVEN(짝수) 일 것. 정렬 순서는 상관없고 중복제거 MSS..