On Sat, 25 Aug 2012 14:47:35 -0600, "Littlefield, Tyler"
<ty...@tysdomain.com> declaimed the following in
gmane.comp.python.general:
Hello all:
I had a quick question.
In my game, I have an is-a setup, where all objects contain data like an
id for sqlalchemy, a name, a description and a list of contents.
Well, a "list of contents" comes down to a table of items with a
foreign key to the item "containing" them...
create table objects
(
ID integer auto-increment primary key,
name varchar(?),
description varchar(?)
)
1, Wulfraed, something or other
2, Bag of Holding, whatever
3, Sword, some cutting comments
4, Treasure Chest, everyone wants one
create table holdings
(
ID integer auto-increment primary key,
holder integer foreign key objects(ID),
holding integer foreign key objects(ID)
)
1, 1, 2
2, 1, 3
3, 2, 4
In order to add functionality to an object, you add components. So for
example, a player would have the Player and Living component associated
create table attribute_types
(
ID integer auto-increment primary key,
name varchar(?),
type char(?), #or an enumeration if supported by the RDBM
#and SQLAlchemy
)
1, Player, Boolean
2, Living, Boolean
3, EdgeWeapon, Boolean
4, Damage, DieRoll
5, ContainerSize, Integer
6, Class, Text
create table attributes
(
ID integer auto-increment primary key,
describes integer foreign key objects(ID),
attribute integer foreign key attribute_types(ID),
value BLOB(?)
)
1, 1, 1, blob(True)
2, 1, 2, blob(True)
3, 3, 3, blob(True)
4, 3, 4, blob("1D8 + 4")
5, 2, 5, blob(-1) #-1 being unlimited, bag of holding
6, 4, 5, blob(6) #treasure chest holds 6 units of objects
7, 1, 6, blob("Ranger")
Now, you could add another layer of indirection -- a table of
pre-defined object /types/ (different types of containers, swords, other
weapons), and have each instance (the ones shown in "objects") refer to
the object type table, and the object type table is what the object
attributes refers to.
