STUDY/SQL_HACKERRANK
[SQL] Manipulation
BOTTLE6
2021. 8. 21. 20:05
코드카데미(codecademy) SQL 연습해보기
https://www.codecademy.com/courses/learn-sql/lessons/manipulation/exercises/manipulation-review
Cheating Sheet
https://www.codecademy.com/learn/learn-sql/modules/learn-sql-manipulation/cheatsheet
LESSON 1 Manipulation
CREATE TABLE
CREATE TABLE celebs (
id INTEGER,
name TEXT,
age INTEGER
);
INSERT TABLE
INSERT INTO celebs (id, name, age)
VALUES (1, 'Justin Bieber', 22);
INSERT INTO celebs (id, name, age)
VALUES (2, 'Beyonce Knowles', 33);
INSERT INTO celebs (id, name, age)
VALUES (3, 'Jeremy Lin', 26);
INSERT INTO celebs (id, name, age)
VALUES (4, 'Taylor Swift', 26);
ALTER TABLE
ALTER TABLE celebs
ADD COLUMN twitter_handle TEXT;
SELECT * FROM celebs;
UPDATE
UPDATE celebs
SET twitter_handle = '@taylorswift13'
WHERE id = 4;
SELECT * FROM celebs;
DELETE
DELETE FROM celebs
WHERE twitter_handle IS NULL;
SELECT * FROM celebs;
CONSTRAINTS
CREATE TABLE celebs (
id INTEGER PRIMARY KEY,
name TEXT UNIQUE,
date_of_birth TEXT NOT NULL,
date_of_death TEXT DEFAULT 'Not Applicable'
);
CREATE TABLE awards (
id INTEGER PRIMARY KEY,
recipient TEXT NOT NULL,
award_name TEXT DEFAULT 'Grammy'
);