SQL Basic Cheat -2- ( 집계함수, 데이터 정렬하기, SQL 문자열 자르기)

SQL Basic Cheat Sheet 스터디 기록 3. 집계함수 COUNT, SUM, AVG, MAX/MIN GROUP BY, HAVING 4. 정렬하기 ORDER BY LIMIT 5. 문자열 함수 LEFT, RIGHT, SUBSTR(SUBSTRING) 6. SQL 소수점 처리 1) COUNT SELECT COUNT(*) FROM sample; >5 SELECT COUNT(Name) FROM sample; >4 SELECT COUNT(DISTINCT Name) FROM sample; >3 2) SUM SELECT SUM(Visits) FROM sample; 3) AVG SELECT AVG(Visits) FROM sample; > (1+2+3+5)/4 = 2.75 SELECT SUM(Visits)/COU..
Data Analystics/SQL 2022. 1. 9. 22:00
SQL Basic Cheat -1- ( 조건문, 비교연산자, Like, IN, Between, Isnull)

SQL Basic Cheat Sheet 스터디 기록 SQL 쿼리 순서 1. SELECT 2. FROM 3. WHERE 4. GROUP BY 5. ORDER BY 6. LIMIT 1. 조건에 맞는 데이터 검색하기 1) 조건문 (WHERE) SELECT * FROM table1 WHERE col1 > 30; 2) 비교연산자(=, >, >=,
Data Analystics/SQL 2022. 1. 9. 21:42
1