drop table if exists customers;
create table customers (
    id int not null auto_increment primary key,
    name varchar(80),
    password varchar(80),
    email varchar(80),
    -- other columns
);

drop table if exists accounts;
create table accounts (
    number varchar(16) not null primary key, -- ignores BSB/number distinction
    name varchar(80) not null,
    customer_id int foreign key references customer(id),
    balance float(10,2) not null
);

drop table if exists transfers;
create table transfers (
    id int not null auto_increment primary key,
    source_account foreign key references accounts(number), -- from-account
    destination_account foreign key references accounts(number), -- to-account
    'time' timestamp not null,
    amount float(10,2) not null,
    description varchar(40)
);

drop table if exists billers;
create table billers (
    code int not null,
    name varchar(40) not null,
    nickname varchar(40),
    customer_number int not null,
    primary_key (code, customer_number)    
)

drop table if exist payments;
create table payments (
    id int not null auto_increment primary key,
    source_account foreign key references accounts(number), -- from-account
    destination_biller foreign key references billers(code), -- to-biller
    'time' timestamp not null,
    amount float(10,2) not null,
)