dorm.tree

Helpers de adjacency-list / recursive CTEs.

Recetas en Recursive CTE.

API

dorm.tree.descendants_cte(model: Any, *, parent_field: str, root_pk: Any, fields: list[str] | None = None, pk_column: str = 'id', cte_name: str = 'descendants', cycle_field: str | None = None) -> CTE

Build a :class:CTE whose rows are every descendant of root_pk in model's adjacency list (rooted at the row whose PK equals root_pk).

Parameters:

Name	Type	Description	Default
model	Any	the dorm Model whose table backs the tree.	required
parent_field	str	the self-referential FK column (typically the <name>_id form generated by :class:~dorm.fields.ForeignKey).	required
root_pk	Any	the PK value to start the walk from.	required
fields	list[str] | None	columns to project. Defaults to [pk_column, parent_field].	None
pk_column	str	the PK column name. Defaults to "id".	'id'
cte_name	str	identifier for the CTE inside the surrounding statement. Defaults to "descendants".	'descendants'
cycle_field	str | None	when set, adds a visited array column and a cycle-detection clause that stops the recursion at the first repeated PK. Useful for cyclic graphs (PG only — SQLite has no array literal).	None

dorm.tree.ancestors_cte(model: Any, *, parent_field: str, leaf_pk: Any, fields: list[str] | None = None, pk_column: str = 'id', cte_name: str = 'ancestors') -> CTE

Build a recursive CTE that walks upward from leaf_pk along parent_field until parent_field is NULL.

See :func:descendants_cte for argument semantics.

dorm.tree.descendants(model: Any, *, parent_field: str, root_pk: Any, pk_column: str = 'id', using: str = 'default')

Convenience: return a list of dicts {pk_column, parent_field} representing every descendant of root_pk. Equivalent to building :func:descendants_cte and consuming it via raw SQL.

For richer column projections, build the CTE directly and stitch it into your own with_cte()-shaped queryset.

dorm.tree.ancestors(model: Any, *, parent_field: str, leaf_pk: Any, pk_column: str = 'id', using: str = 'default')

Convenience inverse of :func:descendants. Returns rows from the leaf upward (root last).