Cypher Query Language Reference¶

Quick Reference Card¶

Pattern Matching¶

-- Node patterns
(n)                         -- Any node
(n:Person)                  -- Node with label
(n:Person {name: 'Alice'})  -- Node with label and properties

-- Relationship patterns
-[r]->                      -- Any directed relationship
-[r:KNOWS]->               -- Typed relationship
-[r:KNOWS {since: 2020}]-> -- Relationship with properties
-[r*1..3]->                -- Variable length (1 to 3 hops)
-[r]-                      -- Undirected relationship

MATCH Clauses¶

-- Basic match
MATCH (n:Person) RETURN n

-- Pattern with relationship
MATCH (a:Person)-[:KNOWS]->(b:Person) RETURN a, b

-- Variable-length paths
MATCH (a)-[:KNOWS*1..3]->(b) RETURN a, b

-- Multiple patterns
MATCH (a:Person), (b:Person)
WHERE a.age > b.age
RETURN a, b

WHERE Conditions¶

-- Comparison
WHERE n.age > 18
WHERE n.name = 'Alice'
WHERE n.age >= 18 AND n.age <= 65

-- String operations
WHERE n.name STARTS WITH 'A'
WHERE n.name ENDS WITH 'son'
WHERE n.name CONTAINS 'ali'

-- Null checks
WHERE n.email IS NOT NULL
WHERE n.phone IS NULL

-- List operations
WHERE n.age IN [18, 21, 25]
WHERE n.tags CONTAINS 'developer'

-- Existence
WHERE EXISTS { MATCH (n)-[:KNOWS]->() }

CREATE Statements¶

-- Create node
CREATE (n:Person {name: 'Alice', age: 30})

-- Create relationship
MATCH (a:Person {name: 'Alice'}), (b:Person {name: 'Bob'})
CREATE (a)-[:KNOWS {since: 2020}]->(b)

-- Create path
CREATE (a:Person {name: 'Alice'})-[:KNOWS]->(b:Person {name: 'Bob'})

UPDATE Operations¶

-- Set properties
MATCH (n:Person {name: 'Alice'})
SET n.age = 31, n.city = 'NYC'

-- Add label
MATCH (n:Person {name: 'Alice'})
SET n:Employee

-- Remove property
MATCH (n:Person {name: 'Alice'})
REMOVE n.age

-- Replace all properties
MATCH (n:Person {name: 'Alice'})
SET n = {name: 'Alice Smith', age: 31}

DELETE Operations¶

-- Delete relationship
MATCH (a)-[r:KNOWS]->(b)
DELETE r

-- Delete node (must delete relationships first)
MATCH (n:Person {name: 'Alice'})
DELETE n

-- Delete node and relationships
MATCH (n:Person {name: 'Alice'})
DETACH DELETE n

Aggregations¶

-- Count
MATCH (n:Person) RETURN count(n)

-- Sum, Avg, Min, Max
MATCH (n:Person) RETURN avg(n.age), min(n.age), max(n.age)

-- Group by
MATCH (n:Person)
RETURN n.city, count(n), avg(n.age)

-- Collect
MATCH (p:Person)-[:KNOWS]->(f)
RETURN p.name, collect(f.name) AS friends

Ordering and Limiting¶

-- Order by
MATCH (n:Person)
RETURN n.name, n.age
ORDER BY n.age DESC

-- Limit
MATCH (n:Person)
RETURN n
LIMIT 10

-- Skip
MATCH (n:Person)
RETURN n
ORDER BY n.age
SKIP 10
LIMIT 10

Functions¶

String Functions:

RETURN toLower('HELLO')           -- 'hello'
RETURN toUpper('hello')           -- 'HELLO'
RETURN trim('  hello  ')          -- 'hello'
RETURN substring('hello', 0, 3)   -- 'hel'

Math Functions:

RETURN abs(-5)                    -- 5
RETURN round(3.14159)             -- 3
RETURN ceil(3.1)                  -- 4
RETURN floor(3.9)                 -- 3
RETURN sqrt(16)                   -- 4

List Functions:

RETURN size([1,2,3])              -- 3
RETURN head([1,2,3])              -- 1
RETURN tail([1,2,3])              -- [2, 3]
RETURN range(1, 10)               -- [1,2,3,4,5,6,7,8,9,10]

Path Functions:

MATCH p = (a)-[:KNOWS*1..3]->(b)
RETURN length(p), nodes(p), relationships(p)

Complex Queries¶

Shortest Path:

MATCH p = shortestPath((a:Person {name: 'Alice'})-[:KNOWS*..5]->(b:Person {name: 'Bob'}))
RETURN p

All Shortest Paths:

MATCH p = allShortestPaths((a)-[:KNOWS*..5]->(b))
WHERE a.name = 'Alice' AND b.name = 'Bob'
RETURN p

CASE Expressions:

MATCH (n:Person)
RETURN n.name,
  CASE
    WHEN n.age < 18 THEN 'Minor'
    WHEN n.age >= 18 AND n.age < 65 THEN 'Adult'
    ELSE 'Senior'
  END AS ageGroup

UNION:

MATCH (n:Person) RETURN n.name
UNION
MATCH (n:Company) RETURN n.name

WITH Clause (pipeline):

MATCH (n:Person)
WITH n, n.age AS age
WHERE age > 18
RETURN n.name, age
ORDER BY age DESC
LIMIT 5

Performance Tips¶

Use indexes for frequent lookups
Add LIMIT when possible
Use PROFILE to analyze queries
Avoid Cartesian products
Use variable-length paths carefully

Example Query Plan:

PROFILE
MATCH (a:Person)-[:KNOWS*1..3]->(b:Person)
WHERE a.name = 'Alice'
RETURN b.name
LIMIT 10

HeliosDB Extensions¶

HTAP Hints¶

-- Force OLTP execution
MATCH /*+ OLTP */ (n:Person {id: 123}) RETURN n

-- Force OLAP execution
MATCH /*+ OLAP */ (n:Person) RETURN count(n), avg(n.age)

-- Suggest index usage
MATCH (n:Person /*+ INDEX(name) */) WHERE n.name = 'Alice' RETURN n

Vector Similarity (HeliosDB Extension)¶

-- Find similar nodes by embedding
MATCH (n:Document)
WHERE vectorSimilarity(n.embedding, $queryEmbedding) > 0.8
RETURN n.text, vectorSimilarity(n.embedding, $queryEmbedding) AS score
ORDER BY score DESC
LIMIT 10

Geospatial Queries (HeliosDB Extension)¶

-- Find nearby locations
MATCH (n:Location)
WHERE distance(n.coordinates, point({latitude: 40.7128, longitude: -74.0060})) < 1000
RETURN n.name, distance(n.coordinates, point({latitude: 40.7128, longitude: -74.0060})) AS distanceMeters
ORDER BY distanceMeters

Full-Text Search (HeliosDB Extension)¶

-- Full-text search on properties
MATCH (n:Document)
WHERE fulltext(n.content, 'machine learning graph database')
RETURN n.title, fulltextScore(n.content, 'machine learning graph database') AS score
ORDER BY score DESC
LIMIT 10

Complete Syntax Guide: 100+ pages in full documentation Last Updated: November 14, 2025