프로그래밍 언어 및 기타/SQL
codecamedy의 learn SQL 4. Multiple Tables
https://www.codecademy.com/learn/learn-sql SQL Tutorial: Learn SQL For Free | Codecademy Learn SQL - a language used to communicate with databases using SQL and learn how to write SQL queries. www.codecademy.com 1. Combining Tables with SQL SELECT * FROM orders JOIN customers ON orders.customer_id = customers.customer_id; 내가 보고싶은 주 테이블은 orders. 여기에 customers의 추가 정보를 붙이고 싶다. join을 한다. 여기에 where를 ..
codecamedy의 learn SQL 3. Aggregate Functions
https://www.codecademy.com/learn/learn-sql SQL Tutorial: Learn SQL For Free | Codecademy Learn SQL - a language used to communicate with databases using SQL and learn how to write SQL queries. www.codecademy.com 1. Count SELECT COUNT(*) FROM table_name; 해당하는 조건의 row 갯수. 2. Sum SELECT SUM(downloads) FROM fake_apps; 해당하는 조건의 row 들의 합. 3. Max / Min SELECT MAX(downloads) FROM fake_apps; 해당하는 조건의 row..
codecamedy의 learn SQL 2. Queries
https://www.codecademy.com/learn/learn-sql 1. SELECT SELECT * FROM table_name; SELECT column1, column2 FROM table_name; table의 column의 값들 확인 2. As SELECT name AS 'Titles' FROM movies; 3. Distinct SELECT DISTINCT tools FROM inventory; 4. Where SELECT * FROM movies WHERE imdb_rating > 8; 5. Like SELECT * FROM movies WHERE name LIKE 'Se_en'; where에 등호 대신 like를 써서 정규식 비슷한게 가능하다. _ 엔 아무 글자나 가능. 한 글자...
codecamedy의 learn SQL 1. Manipulation
https://www.codecademy.com/learn/learn-sql SQL Tutorial: Learn SQL For Free | Codecademy Learn SQL - a language used to communicate with databases using SQL and learn how to write SQL queries. www.codecademy.com Learn how to use SQL to access, create, and update data stored in a database. 딱 봐도 까먹을 각이라 적어놓는다. 1. SELECT SELECT * FROM celebs; 2. CREATE CREATE TABLE celebs ( id INTEGER, name TEXT, a..