create table MyCustomers (
    cid number(6,0) primary key,
    name varchar2(50),
    address varchar2(100)
);

create table MyAccounts (
    aid number(10,0) primary key,
    openAt date,
    balance number(12, 2),
    owner number(6,0) references MyCustomers
);

alter table MyCustomers
add email varchar2(100);

insert into MyCustomers (cid, name, address)
values (1, 'Gary Barry', '101 Main Street');

insert into MyCustomers (cid, name, address)
values (2, 'Mary Sanly', '22 Baker Street');

insert into MyAccounts (aid, openAt, balance, owner)
values (1001, to_date('2019-05-15', 'yyyy-mm-dd'), 350, 1);

insert into MyAccounts (aid, openAt, balance, owner)
values (1002, to_date('Jan 06, 2020', 'Mon dd, yyyy'), 15.5, 1);

insert into MyAccounts (aid, openAt, balance, owner)
values (2001, to_date('12/20/2019', 'mm/dd/yyyy'), 30000, 2);

insert into MyAccounts (aid, openAt, balance, owner)
values (2002, to_date('15/01/2020', 'dd/mm/yyyy'), 1507, 2);

insert into MyCustomers (cid, name, address, email)
(select employee_id, first_name || ' ' || last_name,
        street_address || ', ' || city || ', ' || state_province,
        email
 from hr.employees E, hr.departments D, hr.locations L
 where E.department_id = D.department_id
       and D.location_id = L.location_id);

delete
from MyAccounts
where aid = 2002;

delete
from MyAccounts
where owner = some (select cid
                    from MyCustomers
                    where name like '% King');

update MyAccounts
set balance = balance + 50
where balance < 500;

drop table MyAccounts;
drop table MyCustomers;