I am trying to combine the result of two MATCH statements.
for example like this
MATCH (a)-[:connection]-(b:labelB)
WHERE a.id IN $selection
WITH COLLECT(a) + COLLECT(b) AS selection
However, the issue with this is that it produces a list of type List<node> instead of node. This is an issue because it does not enable another MATCH statement using selection.
Meaning this would not be possible as a continuation to the query:
MATCH (selection)-[]-(c)
RETURN c
This behavior can be achieved by a UNION but it seems to behave unexpectedly when using the result of the first MATCH in the second MATCH.
MATCH (a)
WHERE a.id IN $selection
RETURN a AS selection
UNION
MATCH (a)-[]-(b)
RETURN b AS selection
How can I combine two Nodes into a single value?
You can use UNWIND which is similar to a WHILE looping in sql.
MATCH (a)-[:connection]-(b:labelB)
WHERE a.id IN $selection
WITH COLLECT(a) + COLLECT(b) AS selections
UNWIND selections as selection
MATCH (selection)-[]-(c)
RETURN c