Neo4j Optional MATCH Clause
The Neo4j Optional MATCH clause is used to search for the pattern described in it, while using nulls for missing parts of the pattern.
It is similar to MATCH clause; the only difference is that if it finds the missing parts of the pattern then it returns null as the result.
Let's take an example of Optional match to retrieve the relations from the node ICCT2013. Since there are no such nodes, it returns null.