Thanks again for the help, and thank you very much for the links! I have been looking for examples of django rpgs with little success. Once I get something functional I plan to contribute to the open-source community as well.
Cheers. -Tim On Fri, Feb 19, 2010 at 3:02 PM, Tim Shaffer <timster...@gmail.com> wrote: > You should be able to list all of a samurai's items by doing the > following: > > samurai = Samurai.objects.get(pk=1) > for inv in samurai.inventory_set.all(): > print inv.item.name > > samurai.inventory_set returns a QuerySet the same way that > Inventory.objects returns a QuerySet, but it only returns inventory > items belonging to that specific samurai. > > So this: > > s = Samurai.objects.get(pk=1) > s.inventory_set.all() > > Is essentially the same as doing this: > > s = Samurai.objects.get(pk=1) > Inventory.objects.filter(samurai=s) > > I've actually also researched RPG-like environments in Django. Check > out these links, if you haven't already, for some sample code. Seems > to be the best I've found so far. > > http://code.google.com/p/django-mmo/ > > http://www.rkblog.rk.edu.pl/w/p/code-snapshot-ice-isle-django-web-crpg-game/ > http://github.com/batiste/django-rpg > > sounds like it could be a great project. have fun! > > On Feb 19, 2:18 pm, Timothy Kinney <timothyjkin...@gmail.com> wrote: > > Hi Tim, > > > > Thanks for the concrete examples. I actually had exactly what you had > coded > > last night, but I got rid of it because having multiple inventories for a > > single samurai seemed counter-intuitive to me. But it sounds like it's > the > > best way to get the granularity I want. > > > > Going back to that system I have a different problem then. If I want to > list > > all of the items that a samurai has in his inventory I would like to use > a > > samurai.item_set method, but this method fails with multiple inventories. > It > > also didn't seem to work with a samurai.inventory_set method. > > > > I'm okay with having multiple inventories for one samurai, but what is > the > > best practice for accessing them all as one inventory? > > > > I apologize for the intensive questioning. I hope this discussion is > helping > > other users who are new to django. I had searched extensively for django > > implementations of RPG-like inventories and characters and didn't find > any. > > I'm sure there are other people in the same boat. > > > > Cheers. > > > > -Tim > > > > On Fri, Feb 19, 2010 at 7:49 AM, Tim Shaffer <timster...@gmail.com> > wrote: > > > Basically what you are trying to do is called a many-to-many > > > relationship with an intermediary table. > > > > > If it was a regular many-to-many relationship, you could just do > > > ManyToManyField(Item) on the samurai model, and there would be a table > > > with a foreign key to item, and a foreign key to samurai, and nothing > > > else. But since you need to specify attributes about each of those > > > relationships (in this case, condition), you have to use an > > > intermediary table (Inventory) with those foreign keys, plus your > > > additional attributes. It's not uncommon thing to do at all. > > > > > So if you are using an Inventory class like that, you would want to > > > have this: > > > > > item = models.ForeignKey(Item) > > > > > instead of this: > > > > > item_id = models.ManyToManyField(Item) > > > > > Think of one inventory record as one item belonging to one samurai, > > > with a condition. So if a samurai has more than one of the same same > > > item, he would have more than one inventory record. > > > > > If you were creating your models starting from scratch, you might come > > > up with Inventory usage that looks something like this (pseudo code): > > > > > Inventory.create(samurai='Tim', item='Item 1', condition='100%') > > > Inventory.create(samurai='Tim', item='Item 1', condition='75%') > > > Inventory.create(samurai='Tim', item='Item 2', condition='100%') > > > > > Looking at this, you can determine that each inventory has only one > > > item (foreign key to item), one samurai (foreign key to samurai), and > > > one condition (just an integer). So then you can take that and > > > translate it to a Django model: > > > > > class Inventory(models.Model): > > > samurai = models.ForeignKey('Samurai') > > > item = models.ForeignKey(Item) > > > condition = models.IntegerField(default=100, blank=True, > > > verbose_name='condition') > > > > > Hope this helps. > > > > > On Feb 19, 3:53 am, Timothy Kinney <timothyjkin...@gmail.com> wrote: > > > > Okay, I'm still lacking understanding on the inventory part. Here's > what > > > I > > > > have so far: > > > > > > class Inventory(models.Model): > > > > id = models.AutoField(primary_key=True, verbose_name="inventory") > > > > samurai_id = models.ForeignKey('Samurai') > > > > item_id = models.ManyToManyField(Item) > > > > condition = models.IntegerField(default=100, blank=True, > > > > verbose_name='condition') > > > > > > This has almost all the functionality I want. I can assign a single > > > > inventory to a single samurai, and I can add multiple items to the > > > > inventory. The problem is that I can't associate a unique condition > (100% > > > or > > > > less) with each item. And I can't seem to add the same item twice. > > > > > > I would like to have an inventory that looked like this: > > > > > > Inventory for Samurai Sam: > > > > (item - condition) > > > > Item1 - 100% > > > > Item1 - 75% > > > > Item2 - 100% > > > > > > -Tim > > > > > > On Thu, Feb 18, 2010 at 7:27 PM, Tim Shaffer <timster...@gmail.com> > > > wrote: > > > > > 1) You can change this in your model. Check out "verbose_name" and > > > > > "verbose_name_plural" for the model's Meta class. > > > > > > >http://docs.djangoproject.com/en/dev/ref/models/options/ > > > > > > > 2) If you have a ManyToMany field to samurai on the item, you don't > > > > > need the inventory model at all. A samurai's inventory could be > > > > > obtained by doing "samurai.item_set" and it would return all their > > > > > items. There are different reasons to do each one. However..... > > > > > > > 3) Duplicates can be done by using the Inventory model. You could > > > > > either add a new field called quantity, or simply have multiple > > > > > Inventory records per item and samurai. If each item can have > specific > > > > > attributes (for example, I can have 2 of the same item, one of > which > > > > > has 55% durability, and the other has 70% durability) you would > want > > > > > to have separate records, and could put these attributes on the > > > > > inventory model or item model. But if each item is the same, it's > > > > > easier to just use a quantity field. > > > > > > > 4) If status is a field that could have changing options, create a > > > > > Status model and do a ForiegnKey(Status) on the item. If the > choices > > > > > aren't going to change frequently, the choices field could be an > > > > > Integer or String field and use the Django choices functionality. > > > > > > >http://www.djangoproject.com/documentation/models/choices/ > > > > > > > I gather that you may not have a ton of experience working with > > > > > relational databases. Perhaps an article on basic database design > > > > > might help. It's best to really understand how a relational > database > > > > > works and should be designed before trying to work with Django's > ORM. > > > > > > > > http://www.deeptraining.com/litwin/dbdesign/FundamentalsOfRelationalD. > > > .. > > > > > > > On Feb 18, 3:17 pm, Timothy Kinney <timothyjkin...@gmail.com> > wrote: > > > > > > Hello, I'm new to Django, but learning as fast as I can. I would > > > > > > appreciate some technical help and some database design advice... > > > > > > > > ** > > > > > > 1) Admin pluralizing question > > > > > > > > So I have three models: samurai, item, inventory > > > > > > > > When I login to the admin screen it has chosen to pluralize them > as: > > > > > > samurais, items, inventorys > > > > > > > > I'm a little bit anal, so this bothers me. Where can I change it > to: > > > > > > samurai, items, inventories ? > > > > > > > > ** > > > > > > 2) Model relationships question > > > > > > > > Can someone validate that I am using the right relations for > these? > > > > > > Users will login with a unique id and instantiate a samurai, each > > > > > > possessing various attributes (not shown below). Items have > unique > > > IDs > > > > > > but many samurai can have many of the same items (including > > > > > > duplicates)- also the items have a status as to the condition of > the > > > > > > item. There is one inventory for each samurai which links his > items > > > to > > > > > > him. Based on this system, I believe I should do the following... > > > > > > > > Samurai model: AutoField ID (primary key, unique) > > > > > > Item model: AutoField ID (primary key, unique), > ManyToMany(Samurai) > > > > > > Inventory: Foreignkey(Samurai), ManyToMany(Item) > > > > > > > > Did I do this right? > > > > > > > > ** > > > > > > > > And two design questions: > > > > > > > > 3) How should I implement duplicates of items for a single > inventory? > > > > > > For example, one samurai may have two identical fish. Should I > store > > > > > > this as an additional field in the inventory? If so, how do I > link it > > > > > > to the item id? Is it cleaner/faster/better to use a dictionary? > > > > > > Actually, I've never heard of a dict in SQL. > > > > > > > > 4) How should I implement the status/condition of the items? For > > > > > > example, I want them to be "New", "Used", or "Broken/Unusable". > > > Should > > > > > > I store this in the inventory or in a separate model called > Status? > > > If > > > > > > the latter, should I use a foreignkey(item) and > OneToOne(Inventory) > > > or > > > > > > something else? > > > > > > > > Thank you very much for your help. If you are aware of any > tutorials > > > > > > or available source code for coding RPGs, browser games, or > > > > > > inventories, I will be happy to follow links and try to learn on > my > > > > > > own. > > > > > > > > -Tim > > > > > > > -- > > > > > You received this message because you are subscribed to the Google > > > Groups > > > > > "Django users" group. > > > > > To post to this group, send email to django-users@googlegroups.com > . > > > > > To unsubscribe from this group, send email to > > > > > django-users+unsubscr...@googlegroups.com<django-users%2bunsubscr...@googlegroups.com> > <django-users%2bunsubscr...@googlegroups.com<django-users%252bunsubscr...@googlegroups.com> > > > > > <django-users%2bunsubscr...@googlegroups.com<django-users%252bunsubscr...@googlegroups.com> > <django-users%252bunsubscr...@googlegroups.com<django-users%25252bunsubscr...@googlegroups.com> > > > > > > > > > . > > > > > For more options, visit this group at > > > > >http://groups.google.com/group/django-users?hl=en. > > > > > -- > > > You received this message because you are subscribed to the Google > Groups > > > "Django users" group. > > > To post to this group, send email to django-us...@googlegroups.com. > > > To unsubscribe from this group, send email to > > > django-users+unsubscr...@googlegroups.com<django-users%2bunsubscr...@googlegroups.com> > <django-users%2bunsubscr...@googlegroups.com<django-users%252bunsubscr...@googlegroups.com> > > > > > . > > > For more options, visit this group at > > >http://groups.google.com/group/django-users?hl=en. > > -- > You received this message because you are subscribed to the Google Groups > "Django users" group. > To post to this group, send email to django-us...@googlegroups.com. > To unsubscribe from this group, send email to > django-users+unsubscr...@googlegroups.com<django-users%2bunsubscr...@googlegroups.com> > . > For more options, visit this group at > http://groups.google.com/group/django-users?hl=en. > > -- You received this message because you are subscribed to the Google Groups "Django users" group. 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