DROP TABLE account_struct CASCADE;
DROP TABLE account CASCADE;

CREATE TABLE account (
	id_ integer not null,
	name_ varchar(255) not null,
	balance_ decimal(10,2) not null default 0.0 
		check (type_ <> 'M' OR balance_ = 0.0),
	type_ char(1) not null 
		check (type_ in ('M', 'D')),
	primary key (id_)
);

CREATE TABLE account_struct (
	left_ varchar not null,
	right_ varchar not null 
		check (right_ = left_ || 'Z'),
	account_id_ integer not null,
	primary key (left_),
	foreign key (account_id_) 
		references account (id_),
	unique (right_),
	unique (account_id_)
);