dbsm_4.sql

drop table employee;
create table employee(
id numeric(7) 	NOT NULL default 1,
last_name 	varchar(25),
first_name 	varchar(25),
DEPT_ID 	numeric(7),
constraint pk_employee_id
primary key(id)
);
--alter table employee
--alter last_name type varchar(60)

--alter table employee
--drop column last_name

--alter table employee
--rename to employee2

alter table employee2
drop constraint pk_employee_id;

alter table employee2
add constraint pk_employee_uid
primary key(id)

--renaming back
alter table employee2
rename to employee;

alter table employee
add constraint fk_employee_dept_id
FOREIGN KEY(dept_id)
references department(id);

alter table employee
alter dept_id type numeric(7);

alter table department
add constraint pk_department_uid
primary key (id);

alter table employee
add salary numeric(7) not null default 0;

alter table employee
add constraint chk_employee_salary
check(salary <= 500);