Removing vertices and edges

Ingestion only adds and updates. To take a vertex or an edge out of a graph, remove it by its identity:

from graflo import GraphEngine, GraphManifest
from graflo.connections import Neo4jConfig

schema = GraphManifest.from_yaml("manifest.yaml").require_schema()
conn_conf = Neo4jConfig.from_env()

engine = GraphEngine()
engine.delete_vertices(conn_conf, schema, "machine", [{"serial": "M-17"}])
engine.delete_edges(
    conn_conf,
    schema,
    ("technician", "machine", "maintains"),
    [({"badge": "T-4"}, {"serial": "M-17"})],
)

Pass the schema the graph was written with. Names are logical, as in the manifest: each document carries the vertex type's identity fields, and GraFlo translates them to the names the database stores.

• delete_vertices(conn_conf, schema, vertex, key_docs) removes the vertices and every edge that touches them, in any edge type. A document missing an identity field removes nothing.
• delete_edges(conn_conf, schema, edge_id, endpoints) removes the edges of one declared edge between each (source, target) pair, whatever their properties. edge_id is the edge's (source, target, relation), with relation set to None for an edge declared without one.

Target	Removes
ArangoDB, Neo4j, Memgraph, FalkorDB, TigerGraph, PostgreSQL, NebulaGraph	Vertices with their edges, and edges
File backend	Nothing: its chunks are append-only

Both calls raise ValueError before a connection is opened on a target that cannot remove, and delete_edges also raises it for an edge the schema does not declare.