Advanced Pattern Matching Reference

<h2 id="advanced-pattern-matching-reference" class="position-relative d-flex align-items-center group"> Advanced Pattern Matching Reference <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="advanced-pattern-matching-reference" aria-haspopup="dialog" aria-label="Share link: Advanced Pattern Matching Reference"> Share link </button> </h2><div id="headingShareModal" class="heading-share-modal" role="dialog" aria-modal="true" aria-labelledby="headingShareTitle" hidden> <div class="hsm-dialog" role="document"> <div class="hsm-header"> <h2 id="headingShareTitle" class="h6 mb-0 fw-bold">Share this section</h2> <button type="button" class="hsm-close" aria-label="Close"> </button> </div> <div class="hsm-body"> <label for="headingShareInput" class="form-label small text-muted mb-1 text-uppercase fw-bold" style="font-size: 0.7rem; letter-spacing: 0.5px;">Permalink</label> <div class="input-group mb-4 hsm-url-group"> <input id="headingShareInput" type="text" class="form-control font-monospace" readonly aria-readonly="true" style="font-size: 0.85rem;" /> <button class="btn btn-primary hsm-copy" type="button" aria-label="Copy" title="Copy"> </button> </div> <div class="small fw-bold mb-2 text-muted text-uppercase" style="font-size: 0.7rem; 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'-' [<relationship-detail>] '-' <right-arrow>? <relationship-detail> ::= '[' [<variable>] [<type-expression>] [<quantifier>] [<properties>] ']' </code></pre></div><hr> <h3 id="node-patterns" class="position-relative d-flex align-items-center group"> Node Patterns <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="node-patterns" aria-haspopup="dialog" aria-label="Share link: Node Patterns"> Share link </button> </h3> <h4 id="basic-node-pattern" class="position-relative d-flex align-items-center group"> Basic Node Pattern <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="basic-node-pattern" aria-haspopup="dialog" aria-label="Share link: Basic Node Pattern"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Anonymous node MATCH (n) RETURN n; -- Named node MATCH (person) RETURN person; -- With label MATCH (p:Person) RETURN p; -- Multiple labels MATCH (e:Person:Employee) RETURN e; -- With properties MATCH (p:Person {name: 'Alice', age: 30}) RETURN p; </code></pre></div> <h4 id="label-expressions" class="position-relative d-flex align-items-center group"> Label Expressions <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="label-expressions" aria-haspopup="dialog" aria-label="Share link: Label Expressions"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Single label MATCH (n:Person) -- Multiple labels (AND - node must have all) MATCH (n:Person:Employee) -- Label disjunction (OR - node must have at least one) MATCH (n:Person|Company) -- Label negation MATCH (n:!Deleted) -- Complex label expressions MATCH (n:(Person|Company)&!Archived) </code></pre></div> <h4 id="property-predicates-in-pattern" class="position-relative d-flex align-items-center group"> Property Predicates in Pattern <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="property-predicates-in-pattern" aria-haspopup="dialog" aria-label="Share link: Property Predicates in Pattern"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Equality MATCH (p:Person {name: 'Alice'}) -- Multiple properties MATCH (p:Person {name: 'Alice', active: true}) -- With parameter MATCH (p:Person {email: $email}) -- NULL property (use WHERE instead) MATCH (p:Person) WHERE p.phone IS NULL </code></pre></div><hr> <h3 id="relationship-patterns" class="position-relative d-flex align-items-center group"> Relationship Patterns <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="relationship-patterns" aria-haspopup="dialog" aria-label="Share link: Relationship Patterns"> Share link </button> </h3> <h4 id="direction" class="position-relative d-flex align-items-center group"> Direction <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="direction" aria-haspopup="dialog" aria-label="Share link: Direction"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Outgoing MATCH (a)-[r]->(b) -- Incoming MATCH (a)<-[r]-(b) -- Undirected (either direction) MATCH (a)-[r]-(b) </code></pre></div> <h4 id="relationship-types" class="position-relative d-flex align-items-center group"> Relationship Types <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="relationship-types" aria-haspopup="dialog" aria-label="Share link: Relationship Types"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Single type MATCH (a)-[:KNOWS]->(b) -- Multiple types (OR) MATCH (a)-[:KNOWS|FRIENDS_WITH]->(b) -- Any type (omit type specification) MATCH (a)-[r]->(b) </code></pre></div> <h4 id="relationship-properties" class="position-relative d-flex align-items-center group"> Relationship Properties <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="relationship-properties" aria-haspopup="dialog" aria-label="Share link: Relationship Properties"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- With properties MATCH (a)-[r:KNOWS {since: 2020}]->(b) -- Named with properties MATCH (a)-[friendship:FRIENDS_WITH {since: $year}]->(b) RETURN friendship.trust_level; </code></pre></div><hr> <h3 id="variable-length-paths" class="position-relative d-flex align-items-center group"> Variable-Length Paths <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="variable-length-paths" aria-haspopup="dialog" aria-label="Share link: Variable-Length Paths"> Share link </button> </h3> <h4 id="syntax" class="position-relative d-flex align-items-center group"> Syntax <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="syntax" aria-haspopup="dialog" aria-label="Share link: Syntax"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-bnf" data-lang="bnf"><quantifier> ::= '*' -- Zero or more (Kleene star) | '*' <min> -- At least min | '*' <min> '..' -- At least min (same as above) | '*' '..' <max> -- Zero to max | '*' <min> '..' <max> -- Min to max (inclusive) | '+' equivalent to '*1..' </code></pre></div> <h4 id="examples" class="position-relative d-flex align-items-center group"> Examples <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="examples" aria-haspopup="dialog" aria-label="Share link: Examples"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Any length (0 or more hops) MATCH (a)-[:KNOWS*]->(b) RETURN a, b; -- Exactly 2 hops MATCH (a)-[:KNOWS*2]->(b) RETURN a, b; -- 1 to 3 hops (inclusive) MATCH (a)-[:KNOWS*1..3]->(b) RETURN a, b; -- At least 2 hops MATCH (a)-[:KNOWS*2..]->(b) RETURN a, b; -- Up to 5 hops (0 to 5) MATCH (a)-[:KNOWS*..5]->(b) RETURN a, b; -- One or more hops (+ quantifier) MATCH (a)-[:KNOWS+]->(b) RETURN a, b; </code></pre></div> <h4 id="capturing-path-as-variable" class="position-relative d-flex align-items-center group"> Capturing Path as Variable <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="capturing-path-as-variable" aria-haspopup="dialog" aria-label="Share link: Capturing Path as Variable"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Capture entire path MATCH path = (a:Person {name: 'Alice'})-[:KNOWS*1..3]->(b:Person) RETURN path, length(path) AS hops; -- Access path elements MATCH path = (a)-[:KNOWS*]->(b) RETURN nodes(path) AS all_nodes, relationships(path) AS all_rels, length(path) AS hop_count; </code></pre></div> <h4 id="variable-length-with-multiple-types" class="position-relative d-flex align-items-center group"> Variable-Length with Multiple Types <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="variable-length-with-multiple-types" aria-haspopup="dialog" aria-label="Share link: Variable-Length with Multiple Types"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Multiple relationship types MATCH (a)-[:KNOWS|WORKS_WITH*1..3]->(b) RETURN a.name, b.name; -- Undirected variable-length MATCH (a)-[:KNOWS*1..5]-(b) RETURN a.name, b.name; </code></pre></div><hr> <h3 id="path-patterns" class="position-relative d-flex align-items-center group"> Path Patterns <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="path-patterns" aria-haspopup="dialog" aria-label="Share link: Path Patterns"> Share link </button> </h3> <h4 id="named-paths" class="position-relative d-flex align-items-center group"> Named Paths <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="named-paths" aria-haspopup="dialog" aria-label="Share link: Named Paths"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Assign path to variable MATCH p = (a:Person)-[:KNOWS]->(b:Person)-[:WORKS_AT]->(c:Company) RETURN p; -- Multiple paths MATCH social_path = (a)-[:KNOWS*]->(b), work_path = (b)-[:WORKS_AT]->(c) RETURN social_path, work_path; </code></pre></div> <h4 id="path-functions" class="position-relative d-flex align-items-center group"> Path Functions <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="path-functions" aria-haspopup="dialog" aria-label="Share link: Path Functions"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Path length (number of relationships) MATCH p = (a)-[:KNOWS*]->(b) RETURN length(p) AS hops; -- All nodes in path MATCH p = (a)-[*]->(b) RETURN nodes(p) AS path_nodes; -- All relationships in path MATCH p = (a)-[*]->(b) RETURN relationships(p) AS path_rels; -- First and last nodes MATCH p = (a)-[*]->(b) RETURN head(nodes(p)) AS start_node, last(nodes(p)) AS end_node; </code></pre></div><hr> <h3 id="shortest-path" class="position-relative d-flex align-items-center group"> Shortest Path <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="shortest-path" aria-haspopup="dialog" aria-label="Share link: Shortest Path"> Share link </button> </h3> <h4 id="shortestpath" class="position-relative d-flex align-items-center group"> shortestPath <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="shortestpath" aria-haspopup="dialog" aria-label="Share link: shortestPath"> Share link </button> </h4>Finds a single shortest path between two nodes. <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Shortest path with any relationship type MATCH p = shortestPath((a:Person {name: 'Alice'})-[*]-(b:Person {name: 'Bob'})) RETURN p, length(p) AS distance; -- Shortest path with specific type MATCH p = shortestPath((a:Person {name: 'Alice'})-[:KNOWS*]-(b:Person {name: 'Bob'})) RETURN p; -- With maximum depth MATCH p = shortestPath((a:Person {name: 'Alice'})-[*..10]-(b:Person {name: 'Bob'})) RETURN p; -- With WHERE on path MATCH p = shortestPath((a:Person)-[:KNOWS*]-(b:Person)) WHERE a.name = 'Alice' AND b.name = 'Bob' AND ALL(n IN nodes(p) WHERE n.active = true) RETURN p; </code></pre></div> <h4 id="allshortestpaths" class="position-relative d-flex align-items-center group"> allShortestPaths <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="allshortestpaths" aria-haspopup="dialog" aria-label="Share link: allShortestPaths"> Share link </button> </h4>Finds all paths of the shortest length. <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- All shortest paths MATCH p = allShortestPaths((a:Person {name: 'Alice'})-[*]-(b:Person {name: 'Bob'})) RETURN p, length(p); -- With constraint MATCH p = allShortestPaths((a:City {name: 'Seattle'})-[:CONNECTED*]-(b:City {name: 'Boston'})) WHERE ALL(r IN relationships(p) WHERE r.active = true) RETURN p, [n IN nodes(p) | n.name] AS route; </code></pre></div> <h4 id="shortest-path-performance" class="position-relative d-flex align-items-center group"> Shortest Path Performance <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="shortest-path-performance" aria-haspopup="dialog" aria-label="Share link: Shortest Path Performance"> Share link </button> </h4><table> <thead> <tr> <th>Constraint</th> <th>Impact</th> </tr> </thead> <tbody> <tr> <td>Max depth (<code>*..N</code>)</td> <td>Limits search depth</td> </tr> <tr> <td>Relationship type</td> <td>Reduces edges to traverse</td> </tr> <tr> <td>Direction</td> <td>Reduces edges by 50%</td> </tr> <tr> <td>WHERE on path</td> <td>Applied after finding paths</td> </tr> </tbody> </table> Best practices: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Always specify maximum depth for production queries MATCH p = shortestPath((a)-[*..15]-(b)) -- Reasonable limit RETURN p; -- Use direction when possible MATCH p = shortestPath((a)-[:REPORTS_TO*]->(b)) -- Only outgoing RETURN p; </code></pre></div><hr> <h3 id="quantified-path-patterns" class="position-relative d-flex align-items-center group"> Quantified Path Patterns <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="quantified-path-patterns" aria-haspopup="dialog" aria-label="Share link: Quantified Path Patterns"> Share link </button> </h3> <h4 id="pattern-quantification" class="position-relative d-flex align-items-center group"> Pattern Quantification <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="pattern-quantification" aria-haspopup="dialog" aria-label="Share link: Pattern Quantification"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Repeated pattern MATCH (a)-[:KNOWS]->{1,3}(b) -- 1 to 3 KNOWS relationships RETURN a, b; -- Pattern group quantification MATCH (a)(()-[:KNOWS]->()-[:WORKS_AT]->())+(b) RETURN a, b; </code></pre></div> <h4 id="path-pattern-selectors" class="position-relative d-flex align-items-center group"> Path Pattern Selectors <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="path-pattern-selectors" aria-haspopup="dialog" aria-label="Share link: Path Pattern Selectors"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- TRAIL: No repeated edges MATCH TRAIL (a)-[*]-(b) WHERE a.name = 'Alice' RETURN b; -- ACYCLIC: No repeated nodes MATCH ACYCLIC (a)-[*]-(b) WHERE a.name = 'Alice' RETURN b; -- SIMPLE: No repeated nodes except endpoints can match MATCH SIMPLE (a)-[*]-(b) RETURN a, b; </code></pre></div><hr> <h3 id="pattern-predicates" class="position-relative d-flex align-items-center group"> Pattern Predicates <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="pattern-predicates" aria-haspopup="dialog" aria-label="Share link: Pattern Predicates"> Share link </button> </h3> <h4 id="exists" class="position-relative d-flex align-items-center group"> EXISTS <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="exists" aria-haspopup="dialog" aria-label="Share link: EXISTS"> Share link </button> </h4>Check for pattern existence without returning matches. <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Has at least one KNOWS relationship MATCH (p:Person) WHERE EXISTS { (p)-[:KNOWS]->() } RETURN p.name; -- Complex existence check MATCH (p:Person) WHERE EXISTS { MATCH (p)-[:WORKS_AT]->(c:Company) WHERE c.size > 1000 } RETURN p.name AS enterprise_employee; </code></pre></div> <h4 id="count-in-pattern" class="position-relative d-flex align-items-center group"> COUNT in Pattern <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="count-in-pattern" aria-haspopup="dialog" aria-label="Share link: COUNT in Pattern"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Count matching patterns MATCH (p:Person) WHERE COUNT { (p)-[:KNOWS]->() } > 5 RETURN p.name AS popular_person; -- Relationship count MATCH (p:Person) RETURN p.name, COUNT { (p)-[:KNOWS]->() } AS friend_count; </code></pre></div> <h4 id="all-any-none-single" class="position-relative d-flex align-items-center group"> ALL, ANY, NONE, SINGLE <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="all-any-none-single" aria-haspopup="dialog" aria-label="Share link: ALL, ANY, NONE, SINGLE"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- ALL nodes in path satisfy condition MATCH p = (a)-[:KNOWS*]->(b) WHERE ALL(n IN nodes(p) WHERE n.active = true) RETURN p; -- ANY node in path satisfies condition MATCH p = (a)-[:KNOWS*]->(b) WHERE ANY(n IN nodes(p) WHERE n.verified = true) RETURN p; -- NONE of the nodes satisfy condition MATCH p = (a)-[:KNOWS*]->(b) WHERE NONE(n IN nodes(p) WHERE n.blocked = true) RETURN p; -- Exactly SINGLE node satisfies condition MATCH p = (a)-[:KNOWS*]->(b) WHERE SINGLE(n IN nodes(p) WHERE n.admin = true) RETURN p; </code></pre></div><hr> <h3 id="pattern-comprehensions" class="position-relative d-flex align-items-center group"> Pattern Comprehensions <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="pattern-comprehensions" aria-haspopup="dialog" aria-label="Share link: Pattern Comprehensions"> Share link </button> </h3> <h4 id="list-comprehension-from-pattern" class="position-relative d-flex align-items-center group"> List Comprehension from Pattern <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="list-comprehension-from-pattern" aria-haspopup="dialog" aria-label="Share link: List Comprehension from Pattern"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Collect pattern results into list MATCH (p:Person) RETURN p.name, [(p)-[:KNOWS]->(friend) | friend.name] AS friend_names; -- With filter MATCH (p:Person) RETURN p.name, [(p)-[:KNOWS]->(f:Person) WHERE f.age > 30 | f.name] AS older_friends; -- Nested comprehension MATCH (p:Person) RETURN p.name, [(p)-[:KNOWS]->(f) | { name: f.name, mutual: [(f)-[:KNOWS]->(m) WHERE (p)-[:KNOWS]->(m) | m.name] }] AS friends_with_mutual; </code></pre></div> <h4 id="map-pattern-results" class="position-relative d-flex align-items-center group"> Map Pattern Results <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="map-pattern-results" aria-haspopup="dialog" aria-label="Share link: Map Pattern Results"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Pattern to map MATCH (p:Person) RETURN p.name, [(p)-[r:WORKED_AT]->(c:Company) | { company: c.name, from: r.start_date, to: r.end_date, duration: duration.between(r.start_date, r.end_date) }] AS work_history; </code></pre></div><hr> <h3 id="complex-pattern-examples" class="position-relative d-flex align-items-center group"> Complex Pattern Examples <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="complex-pattern-examples" aria-haspopup="dialog" aria-label="Share link: Complex Pattern Examples"> Share link </button> </h3> <h4 id="social-network-analysis" class="position-relative d-flex align-items-center group"> Social Network Analysis <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="social-network-analysis" aria-haspopup="dialog" aria-label="Share link: Social Network Analysis"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Friends of friends (not direct friends) MATCH (me:Person {name: 'Alice'})-[:KNOWS]->(friend)-[:KNOWS]->(fof:Person) WHERE NOT (me)-[:KNOWS]->(fof) AND me <> fof RETURN DISTINCT fof.name AS recommendation; -- Mutual friends count MATCH (a:Person {name: 'Alice'})-[:KNOWS]->(mutual)<-[:KNOWS]-(b:Person {name: 'Bob'}) RETURN COUNT(mutual) AS mutual_friend_count; -- Influence path MATCH path = (influencer:Person {name: 'Alice'})-[:FOLLOWS*1..4]->(follower:Person) WHERE follower.follower_count > 10000 RETURN path, length(path) AS degrees_of_separation; </code></pre></div> <h4 id="organizational-hierarchy" class="position-relative d-flex align-items-center group"> Organizational Hierarchy <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="organizational-hierarchy" aria-haspopup="dialog" aria-label="Share link: Organizational Hierarchy"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- All reports (direct and indirect) MATCH (ceo:Person {title: 'CEO'})<-[:REPORTS_TO*]-(employee:Person) RETURN employee.name, length(shortestPath((employee)-[:REPORTS_TO*]->(ceo))) AS level; -- Team hierarchy MATCH path = (manager:Person {name: 'Alice'})<-[:REPORTS_TO*0..]-(member:Person) RETURN [n IN nodes(path) | n.name] AS chain, length(path) AS depth; -- Find common manager MATCH (a:Person {name: 'Alice'})-[:REPORTS_TO*]->(manager:Person)<-[:REPORTS_TO*]-(b:Person {name: 'Bob'}) RETURN manager.name AS common_manager ORDER BY length(shortestPath((a)-[:REPORTS_TO*]->(manager))) LIMIT 1; </code></pre></div> <h4 id="graph-algorithms-via-patterns" class="position-relative d-flex align-items-center group"> Graph Algorithms via Patterns <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="graph-algorithms-via-patterns" aria-haspopup="dialog" aria-label="Share link: Graph Algorithms via Patterns"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Triangle detection MATCH (a)-[:KNOWS]->(b)-[:KNOWS]->(c)-[:KNOWS]->(a) WHERE id(a) < id(b) AND id(b) < id(c) -- Avoid duplicates RETURN a.name, b.name, c.name; -- Cycle detection MATCH path = (n)-[*]->(n) WHERE length(path) > 0 RETURN DISTINCT n.name AS node_in_cycle, [m IN nodes(path) | m.name] AS cycle; -- Bridge nodes (connecting different communities) MATCH (a:Person)-[:KNOWS]->(bridge:Person)-[:KNOWS]->(b:Person) WHERE NOT (a)-[:KNOWS*..2]-(b) RETURN bridge.name, COUNT(DISTINCT a) + COUNT(DISTINCT b) AS connections; </code></pre></div> <h4 id="supply-chain" class="position-relative d-flex align-items-center group"> Supply Chain <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="supply-chain" aria-haspopup="dialog" aria-label="Share link: Supply Chain"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Product dependencies MATCH path = (product:Product {name: 'Widget'})-[:REQUIRES*]->(component:Part) RETURN [n IN nodes(path) | n.name] AS dependency_chain; -- Critical path MATCH path = (start:Task {name: 'Start'})-[:DEPENDS_ON*]->(end:Task {name: 'End'}) WITH path, REDUCE(total = 0, t IN nodes(path) | total + t.duration) AS path_duration RETURN path, path_duration ORDER BY path_duration DESC LIMIT 1; -- Single point of failure MATCH (p:Part)<-[:REQUIRES*]-(products:Product) WITH p, COUNT(DISTINCT products) AS dependent_products WHERE dependent_products > 10 RETURN p.name AS critical_component, dependent_products; </code></pre></div><hr> <h3 id="performance-optimization" class="position-relative d-flex align-items-center group"> Performance Optimization <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="performance-optimization" aria-haspopup="dialog" aria-label="Share link: Performance Optimization"> Share link </button> </h3> <h4 id="pattern-selectivity" class="position-relative d-flex align-items-center group"> Pattern Selectivity <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="pattern-selectivity" aria-haspopup="dialog" aria-label="Share link: Pattern Selectivity"> Share link </button> </h4>Order patterns from most selective to least selective: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Good: Start with selective pattern MATCH (p:Person {email: 'alice@example.com'}) -- Unique, indexed MATCH (p)-[:KNOWS*1..3]->(friend) -- Expansion after RETURN friend; -- Bad: Start with broad pattern MATCH (friend:Person) -- All persons MATCH (p:Person {email: 'alice@example.com'})-[:KNOWS*1..3]->(friend) RETURN friend; </code></pre></div> <h4 id="limiting-variable-length-paths" class="position-relative d-flex align-items-center group"> Limiting Variable-Length Paths <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="limiting-variable-length-paths" aria-haspopup="dialog" aria-label="Share link: Limiting Variable-Length Paths"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Always set reasonable bounds MATCH (a)-[:KNOWS*1..5]->(b) -- Max 5 hops -- Use LIMIT early MATCH (a:Person {name: 'Alice'})-[:KNOWS*]->(b) RETURN b LIMIT 100; </code></pre></div> <h4 id="using-explain" class="position-relative d-flex align-items-center group"> Using EXPLAIN <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="using-explain" aria-haspopup="dialog" aria-label="Share link: Using EXPLAIN"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">EXPLAIN MATCH (a:Person {name: 'Alice'})-[:KNOWS*1..3]->(b) RETURN b.name; -- Check for: -- 1. Index usage on starting node -- 2. Estimated rows at each step -- 3. Expansion operator type </code></pre></div><hr> <h3 id="pattern-matching-best-practices" class="position-relative d-flex align-items-center group"> Pattern Matching Best Practices <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="pattern-matching-best-practices" aria-haspopup="dialog" aria-label="Share link: Pattern Matching Best Practices"> Share link </button> </h3> <h4 id="1-anchor-your-patterns" class="position-relative d-flex align-items-center group"> 1. Anchor Your Patterns <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="1-anchor-your-patterns" aria-haspopup="dialog" aria-label="Share link: 1. Anchor Your Patterns"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Good: Start from a specific node MATCH (start:Person {id: 123})-[:KNOWS*]->(end) RETURN end; -- Avoid: Unanchored patterns MATCH ()-[:KNOWS*]->() -- Scans everything </code></pre></div> <h4 id="2-use-direction-when-possible" class="position-relative d-flex align-items-center group"> 2. Use Direction When Possible <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="2-use-direction-when-possible" aria-haspopup="dialog" aria-label="Share link: 2. Use Direction When Possible"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Better: Directed MATCH (a)-[:FOLLOWS]->(b) -- Slower: Undirected (doubles the search space) MATCH (a)-[:FOLLOWS]-(b) </code></pre></div> <h4 id="3-filter-early" class="position-relative d-flex align-items-center group"> 3. Filter Early <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="3-filter-early" aria-haspopup="dialog" aria-label="Share link: 3. Filter Early"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Good: Filter in pattern MATCH (p:Person {active: true})-[:KNOWS]->(f) RETURN f; -- Less efficient: Filter after MATCH (p:Person)-[:KNOWS]->(f) WHERE p.active = true RETURN f; </code></pre></div> <h4 id="4-avoid-unbounded-paths-in-production" class="position-relative d-flex align-items-center group"> 4. Avoid Unbounded Paths in Production <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="4-avoid-unbounded-paths-in-production" aria-haspopup="dialog" aria-label="Share link: 4. Avoid Unbounded Paths in Production"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Dangerous: Can traverse entire graph MATCH (a)-[*]->(b) -- Safe: Bounded depth MATCH (a)-[*..10]->(b) </code></pre></div><hr> <h3 id="related-documentation" class="position-relative d-flex align-items-center group"> Related Documentation <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="related-documentation" aria-haspopup="dialog" aria-label="Share link: Related Documentation"> Share link </button> </h3><ul> <li><a href="/docs/gql/guide/" >GQL Guide</a> - Query language tutorial</li> <li><a href="/docs/gql-reference/specification/" >GQL Specification</a> - ISO standard reference</li> <li><a href="/docs/architecture/query-optimization/" >Query Optimization</a> - Optimizer details</li> <li><a href="/docs/gql/advanced-patterns/" >Advanced GQL Patterns</a> - Tutorial with examples</li> </ul> <hr> Last Updated: January 28, 2026 Geode Version: v0.2.18+ ISO GQL Conformance Profile: ISO/IEC 39075:2024 compliance (see conformance profile)