Neo4j: Creating Multiple Relationships Not Working - neo4j

Question

I am creating multiple relationships in one query. If a match is not found for the first relationship the second one is not created. If both matches exist then both relationships work.
Example:
Assume that 'MATCH1ID' below does not exist but 'MATCH2ID' does. Why does this happen?
DOES NOT WORK
MERGE (NewRecord:OBJECTNAME { Id: 'ABZDEFG' })
SET NewRecord.name='NEWNAME'
WITH NewRecord
MATCH (a)
WHERE a.Id = 'MATCH1ID'
CREATE (a)-[ar:Relationship1]->(NewRecord)
WITH NewRecord MATCH (b)
WHERE b.Id = 'MATCH2ID'
CREATE (b)-[br:Relationship2]->(NewRecord)
(If I switch the order of the node that does exist to be first in the order it works)
WORKS
MERGE (NewRecord:OBJECTNAME { Id: 'ABZDEFG' })
SET NewRecord.name='NEWNAME'
WITH NewRecord
MATCH (b)
WHERE b.Id = 'MATCH2ID'
CREATE (b)-[br:Relationship2]->(NewRecord)
WITH NewRecord
MATCH (a)
WHERE a.Id = 'MATCH1ID'
CREATE (a)-[ar:Relationship1]->(NewRecord)

Answer 1

You can try using a OPTIONAL MATCH instead of a simple MATCH:
MERGE (NewRecord:OBJECTNAME { Id: 'ABZDEFG' })
SET NewRecord.name='NEWNAME'
WITH NewRecord
OPTIONAL MATCH (a)
WHERE a.Id = 'MATCH1ID'
FOREACH(x IN (CASE WHEN a IS NULL THEN [] ELSE [1] END) |
CREATE (a)-[ar:Relationship1]->(NewRecord)
)
WITH NewRecord
OPTIONAL MATCH (b)
WHERE b.Id = 'MATCH2ID'
FOREACH(x IN (CASE WHEN b IS NULL THEN [] ELSE [1] END) |
CREATE (b)-[br:Relationship2]->(NewRecord)
)
Also, this query uses a trick with FORACH and CASE WHEN to handle conditions. In this case, the CREATE statement is executed only when a or b variables are not null.
See Neo4j: LOAD CSV - Handling Conditionals.