Stored Functions

User-defined Cypher functions with typed parameters, default values, schema namespacing, and body caching. Functions can query the graph and document store.

CREATE FUNCTION

CREATE FUNCTION greet(name: STRING) RETURNS STRING AS {
  'Hello, ' + name + '!'
}

-- With default parameter
CREATE FUNCTION greet(name: STRING = 'World') RETURNS STRING AS {
  'Hello, ' + name + '!'
}

-- Graph-reading function
CREATE FUNCTION friend_count(person: STRING) RETURNS INT AS {
  MATCH (p:Person {name: person})-[:FRIEND]->(f) RETURN count(f)
}

-- Document-reading function
CREATE FUNCTION get_email(username: STRING) RETURNS STRING AS {
  MATCH DOCUMENT d IN auth.users WHERE d.username = username RETURN d.email
}

-- Mutating function
CREATE FUNCTION log_event(event: STRING) RETURNS VOID MUTATING AS {
  CREATE DOCUMENT IN audit uuid() {event: event, ts: timestamp()}
}

Calling Functions

-- Inline in queries
MATCH (n:Person) RETURN greet(n.name)

-- With CALL...YIELD
CALL greet('Alice') YIELD result

-- In WHERE clauses
MATCH (n:Person) WHERE friend_count(n.name) > 5 RETURN n.name

Management

CREATE OR REPLACE FUNCTION greet(...) ...
DROP FUNCTION greet
SHOW FUNCTIONS
SHOW FUNCTIONS IN auth

Parameter Types

Schema namespacing: auth.* functions are protected (admin only). Max nesting depth: 16 levels with cycle detection.