Remove Duplicate Relationships

Merges duplicate relationships between the same pair of nodes.

Priority: 2

Details

Finds all cases where multiple relationships of the same type exist between the same two nodes, and merges them using apoc.refactor.mergeRelationships. Properties are overwritten from the latest relationship. Uses apoc.periodic.iterate for batched processing.

Cypher

CALL apoc.periodic.iterate(
  "
  MATCH (a)-[r]->(b)
  WITH a, b, type(r) AS relType, collect(r) AS rels
  WHERE size(rels) > 1
  RETURN rels
  ",
  "
  WITH rels
  CALL apoc.refactor.mergeRelationships(rels, {properties: 'overwrite'})
  YIELD rel
  RETURN 1
  ",
  {batchSize: 100, parallel: false}
)