mnemosine.link.Link.create

Kind: method

Signature

Link.create(cls, storage, source, target, link_type='link', metadata=None)

Documentation

Create and persist a link.

Idempotent: if a link with the same source, target and type already exists, the existing link is returned instead of raising a duplicate key error. Wrapped in a transaction.

Args:

• storage (Storage): The owning storage.
• source (Node | str): Source node or id.
• target (Node | str): Target node or id.
• link_type (str): The link type. Defaults to "link".
• metadata (dict | None): Optional JSON-serializable attributes.

Returns:

• Link: The created (or pre-existing) link.

Raises:

• sqlite3.IntegrityError: If either endpoint does not exist and
• foreign keys are enforced.

Example:

>>> link = Link.create(db, a, b, "relation", {"label": "cites"})
>>> print(link.source_id, "->", link.target_id)
... # doctest: +SKIP