Update value of edge attribute upload LOAD data

Suppose a graph has vertex V and edge E has attribute count where V -> E -> V. There is a load job that reads a csv with 3 fields: FROM, TO, count and loads data for edge E.

Suppose v1 is connected v2 via an edge with count 4 already exist ie., “v1 -(4)-> v2” and one of the entries in new load csv is “v1, v2, 3”.

Is it possible that final output be “v1 -(7)-> v2” instead of “v1 -(3)-> v2”?

Have a look at Add to a “count” attribute inside the loading job post and @Richard_Henderson’s response. That solution might work for you too.