Single-Line Comments

In GQL, single-line comments can be written using either two forward slashes // or two minus signs --. Everything following // or -- on the same line is treated as a comment and ignored during query execution.

MATCH (:User {name: "rowlock"})-[:Follows]->(n:User) // Retrieves users who follow rowlock
RETURN n.name

A path expression should not juxtapose a token that exposes a minus sign on the right (]-, <-, -) followed by a token that exposes a minus sign on the left (-[, ->, -), as this combination introduces the comment symbol --.

This query throws syntax error since it concatenates <- and - without any separators:

MATCH (:User {name: "rowlock"})<--(n:User)
RETURN n

Instead, you can use a space between the two abbreviated edge patterns:

MATCH (:User {name: "rowlock"})<- -(n:User)
RETURN n

Multi-Line Comments

Multi-line comments begin with a forward slash and asterisk (/*) and end with an asterisk and forward slash (*/), allowing for comments that span multiple lines.

/* This query retrieves users who follow rowlock,
and returns all their names */
MATCH (:User {name: "rowlock"})-[:Follows]->(n:User)
RETURN n.name