MYSQL - NodeJS 2

1. CRUD (Create, Read, Update, Delete)

 Create : INSERT INTO 테이블 (컬럼명들) VALUES (값들)

ex) INSERT INTO nodejs.users (name, age, married, comment) VALUES ( 'zero', 24, 0, '자기소개1');

 

 Read : SELECT 컬럼 FROM 테이블명

ex) 1. SELECT * FROM nodejs.users; // 모든 컬럼을 선택

     2. SELECT name , married FROM nodejs. users; //2가지 컬럼을 선택

조건적 선택 WHERE A and(or) B

ex) 1. SELECT * FROM nodejs.users WHERE married =1 AND age > 30;

     2. SELECT * FROM nodejs.users WHERE married =1 OR age > 30;

선택 정렬 ORDER 컬럼 BY DESC(ASC)

ex) 1. SELECT id, name FROM nodejs.users ORDER BY age DESC; // 내림차순 정렬

     2. SELECT id, name FROM nodejs.users ORDER BY age ASC; // 오름차순 정렬

 LIMIT 조회할 개수 제한

ex) SELECT id, name FROM nodejs.users ORDER BY age DESC LIMIT 1;

 OFFSET 조회시 앞의 로우 스킵 기능

ex) SELECT id, name FROM nodejs.users ORDER BY age DESC LIMIT 1 OFFSET 1;//1이면 2번째 부터 조회

 

 Update : UPDATE 테이블명 SET 컬럼=새값 WHERE 조건

ex) UPDATE nodejs.users SET comment = '바꿀 내용' WHERE id = 2;

 

 Delete : DELETE FROM 테이블명 WHERE 조건

ex) DELETE FROM nodejs.users WHERE id =2;