Basic Insert

CREATE DATABASE soft_uni;
USE soft_uni;
CREATE TABLE towns (
id INT NOT NULL PRIMARY KEY AUTO_INCREMENT,
name VARCHAR(255) NOT NULL UNIQUE
);

CREATE TABLE addresses (
id INT NOT NULL PRIMARY KEY AUTO_INCREMENT,
address_text VARCHAR(255),
town_id INT NOT NULL,
FOREIGN KEY (town_id) REFERENCES towns (id)
);


CREATE TABLE departments (
id INT NOT NULL PRIMARY KEY AUTO_INCREMENT,
name VARCHAR(255) NOT NULL UNIQUE
);

CREATE TABLE employees (
id INT NOT NULL PRIMARY KEY AUTO_INCREMENT,
first_name VARCHAR(255),
middle_name VARCHAR(255),
last_name VARCHAR(255),
job_title VARCHAR(255),
department_id INT NOT NULL,
hire_date DATE,
salary INT,
address_id INT,
FOREIGN KEY (department_id) REFERENCES departments (id)
);
ALTER TABLE employees
CHANGE salary salary DOUBLE(6,2);
ALTER TABLE employees
ADD FOREIGN KEY (address_id) REFERENCES addresses (id);

ALTER TABLE employees
CHANGE hire_date hire_date VARCHAR(255);

INSERT INTO towns (name)
VALUES ("Sofia") , ("Plovdiv") , ("Varna") , ("Burgas");

INSERT INTO departments (name)
VALUES ("Engineering") , ("Sales") , ("Marketing") , ("Software Development") , ("Quality Assurance");

INSERT INTO employees (first_name , middle_name , last_name, job_title ,department_id , hire_date , salary , address_id)
VALUES
("Ivan" ,  "Ivanov" ,  "Ivanov" , ".NET Developer" , 1 , "01/02/2013" , 3500.00 , 1),
("Petar" , "Petrov" , "Petrov" , "Senior Engineer" , 2 , "02/03/2004" , 4000.00 , 2),
("Maria" , "Petrova", "Ivanova" , "Intern" , 3 , "28/08/2016" , 525.25 , 3),
("Georgi" , "Terziev" , "Ivanov" , "CEO" , 4 , "09/12/2007" , 3000.00 , 1),
("Peter" , "Pan" , "Pan" , "Intern" , 5 , "28/08/2016" , 599.88 , 2);