What is the difference between multiple MATCH clauses and a comma in a Cypher query?

Question

In a Cypher query language for Neo4j, what is the difference between one MATCH clause immediately following another like this:

MATCH (d:Document{document_ID:2})
         


        

Answer 1

There are no differences between these provided that the clauses are not linked to one another.

If you did this:

MATCH (a:Thing), (b:Thing) RETURN a, b;

That's the same as:

MATCH (a:Thing) MATCH (b:Thing) RETURN a, b;

Because (and only because) a and b are independent. If a and b were linked by a relationship, then the meaning of the query could change.