Update MySQLNotes.md

master
Matt Huntington 10 years ago
parent 21ca43a269
commit 709c456722

@ -22,7 +22,7 @@
SHOW DATABASES; SHOW DATABASES;
CREATE DATABASE users; CREATE DATABASE users;
USE users; USE users;
CREATE TABLE employees (NAME VARCHAR(20), age INT); CREATE TABLE employees (first_name VARCHAR(20), age INT);
DESCRIBE employees; DESCRIBE employees;
-- CRUD -- CRUD
@ -38,8 +38,8 @@ SELECT * FROM employees WHERE age < 63;
SELECT * FROM employees WHERE age > 63; SELECT * FROM employees WHERE age > 63;
SELECT * FROM employees WHERE age >= 63; SELECT * FROM employees WHERE age >= 63;
SELECT * FROM employees WHERE age <= 63; SELECT * FROM employees WHERE age <= 63;
SELECT * FROM employees WHERE NAME first_name LIKE "%Charlie%"; SELECT * FROM employees WHERE first_name first_name LIKE "%Charlie%";
SELECT * FROM employees WHERE NAME first_name NOT LIKE "%Charlie%"; SELECT * FROM employees WHERE first_name NOT LIKE "%Charlie%";
SELECT * FROM employees WHERE age IS NULL; SELECT * FROM employees WHERE age IS NULL;
SELECT * FROM employees WHERE age IS NOT NULL; SELECT * FROM employees WHERE age IS NOT NULL;
@ -52,12 +52,12 @@ SELECT * FROM users WHERE first_name = 'Matt' OR age = 49;
SELECT * FROM employees ORDER BY age DESC; SELECT * FROM employees ORDER BY age DESC;
SELECT * FROM employees ORDER BY age ASC LIMIT 2; SELECT * FROM employees ORDER BY age ASC LIMIT 2;
SELECT * FROM employees ORDER BY age ASC LIMIT 2 OFFSET 1; SELECT * FROM employees ORDER BY age ASC LIMIT 2 OFFSET 1;
SELECT * FROM employees ORDER BY age DESC, NAME ASC; SELECT * FROM employees ORDER BY age DESC, first_name ASC;
-- ALTER TABLE -- ALTER TABLE
ALTER TABLE employees ADD COLUMN weight FLOAT; ALTER TABLE employees ADD COLUMN weight FLOAT;
ALTER TABLE employees DROP COLUMN height; ALTER TABLE employees DROP COLUMN height;
ALTER TABLE employees ADD COLUMN height FLOAT AFTER NAME; ALTER TABLE employees ADD COLUMN height FLOAT AFTER first_name;
ALTER TABLE employees MODIFY COLUMN height FLOAT AFTER age; ALTER TABLE employees MODIFY COLUMN height FLOAT AFTER age;
ALTER TABLE employees ADD COLUMN id INT FIRST; ALTER TABLE employees ADD COLUMN id INT FIRST;
ALTER TABLE employees ADD COLUMN dob DATETIME; ALTER TABLE employees ADD COLUMN dob DATETIME;
@ -72,7 +72,7 @@ SELECT AVG(age) FROM employees;
SELECT MIN(age) FROM employees; SELECT MIN(age) FROM employees;
SELECT MAX(age) FROM employees; SELECT MAX(age) FROM employees;
SELECT GROUP_CONCAT(age) FROM employees; SELECT GROUP_CONCAT(age) FROM employees;
SELECT GROUP_CONCAT(age) FROM employees, name; SELECT GROUP_CONCAT(age) FROM employees, first_name;
-- JOINS -- JOINS
SELECT * from employees FULL JOIN companies; SELECT * from employees FULL JOIN companies;

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