Updating an existing property or creating a new one

If you want to update an existing property or add a new one, it's as simple as the following:

MATCH (n {id: 1})
SET n.name = "Node 1"
RETURN n

The RETURN statement is not mandatory, but it is a way to check the query went well, for instance, checking the Table tab of the result cell:

{
  "name": "Node 1",
  "id": 1
}