create table t_field (
	field_id		bigint auto_increment primary key not null,
	class_id		integer not null references t_class(class_id),
	type_id			tinyint not null references t_type(type_id),
	access_id		tinyint not null references t_access(access_id),
	name			varchar(64) not null,
	value			text null,

	index (field_id),
	unique (field_id),

	index (class_id)
);