Import from JSON where CASE statement would help

Neo4j Graph Platform Import / Export
,
4

Hi Ward -

There is a bit of a hack you can use for this sort of conditional logic that involves creating dummy lists using CASE and then iterating over them. Something like this:

create (s:SOURCE {
  name:'dataflow-diagram',
  title:'Dataflow Diagram'})
with s

UNWIND {json} AS obj
WITH *,
  CASE WHEN obj.type == 'store' THEN [1] ELSE [] END AS stores,
  CASE WHEN obj.type == 'rest' THEN [1] ELSE [] END AS rests,
  CASE WHEN obj.type == 'queue' THEN [1] ELSE [] END AS queues


FOREACH (_ IN stores |
  MERGE (d:DB {name: obj.store})
  MERGE (g:PROGRAM {name: obj.from})
  MERGE (g)-[:QUERIES {source: s.name}]->(d)
)

FOREACH (_ IN rests |
  MERGE (f:PROGRAM {name: obj.from})
  MERGE (t:PROGRAM {name: obj.to})
  MERGE (f)-[:CALLS {source: s.name}]->(t)
)

FOREACH (_ IN queues |
  CREATE (q:QUEUE {name: obj.queue})
  MERGE (r:PROGRAM {name: obj.read})
  MERGE (r)-[:READS {source: s.name}]->(q)
  MERGE (w:PROGRAM {name: obj.write})
  MERGE (w)-[:WRITES {source: s.name}]->(q)
)

Also, do you have uniqueness constraints created for any of the properties you are merging on?

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