atoti.Hierarchy.dimension_default

property Hierarchy.dimension_default: bool

Whether the hierarchy is the default in its dimension or not.

Some UIs support clicking on a dimension (or drag and dropping it) as a shortcut to add its default hierarchy to a widget.

Example

>>> table = session.create_table(
...     "Sales",
...     types={
...         "Product": tt.STRING,
...         "Shop": tt.STRING,
...         "Customer": tt.STRING,
...         "Date": tt.LOCAL_DATE,
...     },
... )
>>> cube = session.create_cube(table, mode="manual")
>>> h = cube.hierarchies
>>> for name in table.columns:
...     h[name] = [table[name]]
...     assert h[name].dimension == table.name

By default, the default hierarchy of a dimension is the first created one:

>>> h["Product"].dimension_default
True
>>> h["Shop"].dimension_default
False
>>> h["Customer"].dimension_default
False
>>> h["Date"].dimension_default
False

There can only be one default hierarchy per dimension:

>>> h["Shop"].dimension_default = True
>>> h["Product"].dimension_default
False
>>> h["Shop"].dimension_default
True
>>> h["Customer"].dimension_default
False
>>> h["Date"].dimension_default
False

When the default hierarchy is deleted, the first created remaining one becomes the default:

>>> del h["Shop"]
>>> h["Product"].dimension_default
True
>>> h["Customer"].dimension_default
False
>>> h["Date"].dimension_default
False

The same thing occurs if the default hierarchy is moved to another dimension:

>>> h["Product"].dimension = "Product"
>>> h["Customer"].dimension_default
True
>>> h["Date"].dimension_default
False

Since Product is the first created hierarchy of the newly created dimension, it is the default one there:

>>> h["Product"].dimension_default
True