Relation Class API Reference

A relation between two nodes in the database. Has a base type, source and target node IDs, and properties from base type.

Relation class is designed to be instanced by an engine:

friendship = engine.create_relation("alice", "bob", "FRIEND")

Note

Relations are designed to be always unique! Even when you load a database from save of another one. It means you have same relation between same nodes, with same type, and even same values. In short, Graphite is a multigraph. They are hashable based on Python's id() function.

Subject To Change

Other type of graphs, is planned to be available.

Attributes:

• type_name (str) –

  Name of base RelationType.

• from_node (str) –

  Source node's ID.

• to_node (str) –

  Target node's ID.

• values (dict[str, Any]) –

  A dictionary holding field values. Use set() and get() methods to use it.

  Tip

  Values can be accessed with node["field_name"] too.

• type_ref (RelationType | None) –

  Reference to RelationType.

Methods:

• get –

  Returns value of a field in this relation.

• set –

  Sets a field in this relation.

Functions

get

get(field_name: str) -> Any

Returns value of a field in this relation.

Parameters:

• field_name (str) –

  Field name.

Returns:

• Any –

  Value.

set

set(field_name: str, value: Any) -> None

Sets a field in this relation.

Parameters:

• field_name (str) –

  Field name.

• value (Any) –

  Value to set.

Subject To Change

Currently type of values can be invalid. This may be fixed in next versions.