Data models & schemas¶

We gonna create two simple databases with a relation quite similar as described in the Notion docs. We gonna have a database for customers and one for items, which customers can purchase.

Let's first initialize a Notion session with

import ultimate_notion as uno

notion = uno.Session.get_or_create()

Declarative schemas & relations¶

We start by defining the schema for our items in a really pythonic way. The schema should have three properties, the title property Name for the name of an item, e.g. "Jeans", a size property Size and of course a Price property numbers in Dollars. The size of of piece of clothing can be chosen from the options S, M and L. We can directly translate this schema into Python code:

class Size(uno.OptionNS):
    """Namespace for the select options of our various sizes"""
    S = uno.Option(name='S', color='green')
    M = uno.Option(name='M', color='yellow')
    L = uno.Option(name='L', color='red')


class Item(uno.PageSchema, db_title='Item DB'):
    """Database of all the items we sell"""
    name = uno.Property('Name', uno.PropType.Title())
    size = uno.Property('Size', uno.PropType.Select(Size))
    price = uno.Property('Price', uno.PropType.Number(uno.NumberFormat.DOLLAR))

Since a database needs to be a block wighin a page, we assume there is a page called Tests, which is connected with this integration. We retrieve the object of this page and create the database with the page as parent page.

root_page = notion.search_page('Tests', exact=True).item()
item_db = notion.create_db(parent=root_page, schema=Item)

Now we create a database for our customers and define a one-way Relation to the items:

class Customer(uno.PageSchema, db_title='Customer DB'):
    """Database of all our beloved customers"""
    name = uno.Property('Name', uno.PropType.Title())
    purchases = uno.Property('Items Purchased', uno.PropType.Relation(Item))

customer_db = notion.create_db(parent=root_page, schema=Customer)

Warning

To create a database that has a relation to another database requires that the target database already exists. Thus the order of creating the databases from the schemas is important.

All available types of a database property are provided by PropType, which is just a namespace for the various property types defined in schema. Property types with the class variable allowed_at_creation set to False are currently not supported by the Notion API. when creating a new database.

New database entries¶

Now that we have created those two databases, we can start filling them with a few entries either using the create_page method of the database object:

t_shirt = item_db.create_page(name='T-shirt', size=Size.L, price=17)
khaki_pants = item_db.create_page(name='Khaki pants', size=Size.M, price=25)
tank_top = item_db.create_page(name='Tank top', size=Size.S, price=15)

or we can also directly use the create method of the schema if the schema is already bound to a database:

lovelace = Customer.create(name='Ada Lovelace', purchases=[tank_top])
hertzfeld = Customer.create(name='Andy Herzfeld', purchases=[khaki_pants])
engelbart = Customer.create(name='Doug Engelbart', purchases=[khaki_pants, t_shirt])

Info

The keyword-arguments are exactly the class variables from the page schemas Item and Customer above.

This is how are two databases item_db and customer_db look like in the Notion UI right now:

Note

The description of the databases corresponds to the the docstring of the schema classes Item and Customer.

Two-way & self relations¶

Notion also supports two-way relations and so does Ultimate Notion. Taking the same example as before, imagine that we also wanted to see direclty which customers bought a specific item. In this case the one-way relation Items Purchased from Customer needs to become a two-way relation. We can achieve this, with a simple modification in both schemas:

class Item(uno.PageSchema, db_title='Item DB'):
    """Database of all the items we sell"""
    name = uno.Property('Name', uno.PropType.Title())
    size = uno.Property('Size', uno.PropType.Select(Size))
    price = uno.Property('Price', uno.PropType.Number(uno.NumberFormat.DOLLAR))
    bought_by = uno.Property('Bought by', uno.PropType.Relation())

class Customer(uno.PageSchema, db_title='Customer DB'):
    """Database of all our beloved customers"""
    name = uno.Property('Name', uno.PropType.Title())
    purchases = uno.Property(
        'Items Purchased',
        uno.PropType.Relation(Item, two_way_prop=Item.bought_by)
    )

So what happens here is that we first create a target relation property bought_by in Item by not specifying any other schema. Then in Customer, we define now a two-way property but specifying not only the schema Item bouth also the property we want to synchronize with using the two_way_prop keyword.

Let's delete the old databases and recreate them with our updates schemas and a few items

item_db.delete(), customer_db.delete()

item_db = notion.create_db(parent=root_page, schema=Item)
customer_db = notion.create_db(parent=root_page, schema=Customer)

t_shirt = item_db.create_page(name='T-shirt', size=Size.L, price=17)
lovelace = Customer.create(name='Ada Lovelace', purchases=[t_shirt])
hertzfeld = Customer.create(name='Andy Herzfeld', purchases=[t_shirt])

and take a look at the two-way relation within item_db:

Assume now that we want to have a schema that references itself, for instance a simple task list like where certain tasks can be subtasks of others:

class Task(uno.PageSchema, db_title='Task List'):
    """A really simple task lists with subtasks"""
    task = uno.Property('Task', uno.PropType.Title())
    due_by = uno.Property('Due by', uno.PropType.Date())
    parent = uno.Property('Parent Task', uno.PropType.Relation(uno.SelfRef))

task_db = notion.create_db(parent=root_page, schema=Task)

from datetime import datetime, timedelta

today = datetime.now()

clean_house = Task.create(
    task='Clean the house',
    due_by=today + timedelta(weeks=4)
)
Task.create(
    task='Vacuum living room',
    due_by=today + timedelta(weeks=1),
    parent=clean_house
)
Task.create(
    task='Tidy up kitchen',
    due_by=today + timedelta(days=3),
    parent=clean_house
)

Warning

Due to a bug in the Notion API, it's not possible to have a two-way self-referencing relation right now. Creating a two-way relation leads to the creation of a one-way relation. We check for that and fail.