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/*BEWARE!*/
drop table if exists node_access;
drop table if exists users;
drop table if exists node_links;
drop table if exists trash;
drop table if exists super_trash;
drop table if exists nodes;
drop trigger if exists delete_on_zero_links;
drop trigger if exists delete_links;
drop trigger if exists del_node;
drop trigger if exists supper_del_node;
create table nodes (
node_id int not null auto_increment,
is_directory boolean default false,
relative_path varchar(500) not null,
type varchar(20) not null default 'data',
code varchar(100) not null default "error",
primary key (node_id)
);
/*base user information*/
create table users (
user_id int not null auto_increment,
username varchar(50) not null unique,
password varchar(255) not null,
email varchar(50),
home_directory int not null,
primary key (user_id),
foreign key (home_directory) references nodes(node_id) on delete cascade
);
create table node_access (
node_id int not null,
user_id int not null,
can_view boolean not null default true,
can_edit boolean not null default false,
foreign key (node_id) references nodes(node_id) on delete cascade,
foreign key (user_id) references users(user_id) on delete cascade
);
/*we can name a node in many different ways */
create table node_links (
directory_id int not null,
node_id int not null,
name varchar(100) not null default 'no name',
note varchar(200) not null default "",
foreign key (directory_id) references nodes(node_id) on delete cascade,
foreign key (node_id) references nodes(node_id) on delete cascade
);
create table trash (
node_id int not null
);
create table super_trash (
node_id int not null
);
create trigger delete_on_zero_links
after delete
on node_links
for each row
insert into trash
select nodes.node_id
from nodes
where nodes.node_id not in (select node_id from node_links) and
(nodes.node_id=old.node_id );
create trigger del_node
after delete
on trash
for each row
insert into super_trash(node_id)
select node_id
from nodes
where nodes.node_id=old.node_id;
create trigger supper_del_node
after delete
on super_trash
for each row
insert into trash
select node_id
from nodes
where nodes.node_id=old.node_id;
create trigger delete_links
before delete
on super_trash
for each row
delete from node_links
where directory_id=old.node_id;
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