Релациона шема

DLL код

create table account(
    id serial primary key,
    username varchar(255) not null,
    password varchar(255) not null,
    balance decimal(15, 2) not null 
);

create table "transaction"(
    id serial primary key,
    amount decimal(15, 2) not null,
    type varchar(50) not null,
    timestamp timestamp default current_timestamp,
    account_id int not null,
    foreign key (account_id) references account(id)
);

create table transfer(
    id serial primary key,
    s_id int not null,
    r_id int not null, 
    foreign key(s_id) references account(id),
    foreign key(r_id) references
    account(id)

);

create table deposit(
    id serial primary key,
    account_id int not null,
    amount decimal(15,2) not null,
    timestamp timestamp default current_timestamp,
    foreign key(account_id) references account(id)
);

create table withdraw(
    id serial primary key,
    account_id int not null,
    amount decimal(15,2) not null,
    timestamp timestamp default current_timestamp,
    foreign key(account_id) references account(id)
);

create table transferred_money(
    id serial primary key, 
    s_account_id int not null, 
    r_account_id int not null, 
    t_id int not null, 
    currency varchar(50) not null, 
    foreign key (s_account_id) references account(id),
    foreign key (r_account_id) references account(id),
    foreign key (t_id) references transaction(id)
);

Triggers