/*
    Table definition as it is now
*/
create table xar_block_group_instances (
  id          int(11) not null auto_increment primary key,
  group_id    int(11) not null default '0' key,
  instance_id int(11) not null default '0' key,
  template    varchar(100)     default '',
  position    int(11) not null default '0',
)

/*
    Table definition with all the refactoring applied manually

    @todo:
        - this table should be called blockgroup_members
*/
create table block_group_instances (
  id          int(11)      unsigned not null auto_increment primary key,
  group_id    int(11)      unsigned not null
    comment 'block group, prevent deletion while it has members'
    references block_groups(id) on delete restrict,
  instance_id int(11)      unsigned not null
    comment 'block instance, when removed, remove it from the block groups it is in too'
    references block_instances(id) on delete cascade, /* if a block is removed, remove it from it's block group too */
  template    varchar(100) default ''
    comment 'template used by this block inside the group',
  position    int(11)      unsigned not null default '0'
    commebnt 'position of block within the group',
) comment 'instances of blocks, within blockgroups'