Category: Graph Query Language (GQL)

The Graph Query Language (GQL) category provides comprehensive documentation on writing queries in Geode using the ISO/IEC 39075:2024 standard. From basic pattern matching to advanced analytical queries, this collection covers everything you need to effectively query graph data. <h3 id="introduction-to-gql" class="position-relative d-flex align-items-center group"> Introduction to GQL <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="introduction-to-gql" aria-haspopup="dialog" aria-label="Share link: Introduction to GQL"> Share link </button> </h3><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; 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align-items: center; justify-content: center; font-size: 0.9rem; padding: 0.6rem; border-color: var(--bs-border-color); width: 100%; } [data-bs-theme="dark"] .hsm-share-grid .btn { color: #e2e8f0; border-color: #475569; } [data-bs-theme="dark"] .hsm-share-grid .btn:hover { background: #334155; border-color: #cbd5e1; } </style> <script> (function(){ const modal = document.getElementById('headingShareModal'); if(!modal) return; const input = modal.querySelector('#headingShareInput'); const copyBtn = modal.querySelector('.hsm-copy'); const twitter = modal.querySelector('#share-twitter'); const linkedin = modal.querySelector('#share-linkedin'); const facebook = modal.querySelector('#share-facebook'); const closeBtn = modal.querySelector('.hsm-close'); let lastFocus=null; let trapBound=false; function buildUrl(id){ return window.location.origin + window.location.pathname + '#' + id; } function isOpen(){ return !modal.hasAttribute('hidden'); } function hydrate(id){ const url=buildUrl(id); input.value=url; const enc=encodeURIComponent(url); const text=encodeURIComponent(document.title); if(twitter) twitter.href=`https://twitter.com/intent/tweet?url=${enc}&text=${text}`; if(linkedin) linkedin.href=`https://www.linkedin.com/sharing/share-offsite/?url=${enc}`; if(facebook) facebook.href=`https://www.facebook.com/sharer/sharer.php?u=${enc}`; } function openModal(id){ lastFocus=document.activeElement; hydrate(id); if(!isOpen()){ modal.removeAttribute('hidden'); } requestAnimationFrame(()=>{ input.focus(); }); trapFocus(); } function closeModal(){ if(!isOpen()) return; modal.setAttribute('hidden',''); if(lastFocus && typeof lastFocus.focus==='function') lastFocus.focus(); } function copyCurrent(){ try{ navigator.clipboard.writeText(input.value).then(()=>feedback(true),()=>fallback()); } catch(e){ fallback(); } } function fallback(){ input.select(); try{ document.execCommand('copy'); feedback(true);}catch(e){ feedback(false);} } function feedback(ok){ if(!copyBtn) return; const icon=copyBtn.querySelector('i'); if(!icon) return; const prev=copyBtn.getAttribute('data-prev')||icon.className; if(!copyBtn.getAttribute('data-prev')) copyBtn.setAttribute('data-prev',prev); icon.className= ok ? 'fa-duotone fa-clipboard-check':'fa-duotone fa-circle-exclamation'; setTimeout(()=>{ icon.className=prev; },1800); } function handleShareClick(e){ e.preventDefault(); const btn=e.currentTarget; const id=btn.getAttribute('data-share-target'); if(id) openModal(id); } function bindShareButtons(){ document.querySelectorAll('.h-share').forEach(btn=>{ if(!btn.dataset.hShareBound){ btn.addEventListener('click', handleShareClick); btn.dataset.hShareBound='1'; } }); } bindShareButtons(); if(document.readyState==='loading'){ document.addEventListener('DOMContentLoaded', bindShareButtons); } else { requestAnimationFrame(bindShareButtons); } document.addEventListener('click', function(e){ const shareBtn=e.target.closest && e.target.closest('.h-share'); if(shareBtn && !shareBtn.dataset.hShareBound){ handleShareClick.call(shareBtn, e); } }, true); document.addEventListener('click', e=>{ if(e.target===modal) closeModal(); if(e.target.closest && e.target.closest('.hsm-close')){ e.preventDefault(); closeModal(); } if(copyBtn && (e.target===copyBtn || (e.target.closest && e.target.closest('.hsm-copy')))) { e.preventDefault(); copyCurrent(); } }); document.addEventListener('keydown', e=>{ if(e.key==='Escape' && isOpen()) closeModal(); }); function trapFocus(){ if(trapBound) return; trapBound=true; modal.addEventListener('keydown', f=>{ if(f.key==='Tab' && isOpen()){ const focusable=[...modal.querySelectorAll('a[href],button,input,textarea,select,[tabindex]:not([tabindex="-1"])')].filter(el=>!el.hasAttribute('disabled')); if(!focusable.length) return; const first=focusable[0]; const last=focusable[focusable.length-1]; if(f.shiftKey && document.activeElement===first){ f.preventDefault(); last.focus(); } else if(!f.shiftKey && document.activeElement===last){ f.preventDefault(); first.focus(); } } }); } if(closeBtn) closeBtn.addEventListener('click', e=>{ e.preventDefault(); closeModal(); }); })(); </script>Graph Query Language (GQL) is the ISO-standardized language for querying graph databases, analogous to SQL for relational databases. Ratified as ISO/IEC 39075:2024, GQL represents decades of graph database research unified into a single, coherent specification. Geode follows the ISO/IEC 39075:2024 compliance to keep queries portable and semantics predictable. GQL adopts a declarative approach: you describe what patterns to find, not how to find them. The query engine determines optimal execution strategies using cost-based optimization, indexes, and graph-specific algorithms. This separation of concerns lets you focus on business logic while Geode handles performance. <h3 id="core-concepts" class="position-relative d-flex align-items-center group"> Core Concepts <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="core-concepts" aria-haspopup="dialog" aria-label="Share link: Core Concepts"> Share link </button> </h3> <h4 id="nodes-and-relationships" class="position-relative d-flex align-items-center group"> Nodes and Relationships <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="nodes-and-relationships" aria-haspopup="dialog" aria-label="Share link: Nodes and Relationships"> Share link </button> </h4>Graphs consist of nodes (entities) and relationships (connections). Nodes have labels that categorize them and properties that store attributes. Relationships have types and can also contain properties. <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Node: (variable:Label {property: value}) (person:Person {name: 'Alice', age: 30}) -- Relationship: -[variable:TYPE {property: value}]-> -[friendship:KNOWS {since: 2020}]-> -- Undirected relationship -[connection:CONNECTED]- </code></pre></div> <h4 id="pattern-matching" class="position-relative d-flex align-items-center group"> Pattern Matching <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" aria-haspopup="dialog" aria-label="Share link: Pattern Matching"> Share link </button> </h4>Pattern matching is the foundation of GQL queries. Use <code>MATCH</code> to describe patterns in the graph, then <code>RETURN</code> to specify what to retrieve: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Find Alice's friends MATCH (alice:Person {name: 'Alice'})-[:KNOWS]->(friend:Person) RETURN friend.name, friend.age </code></pre></div>Patterns describe graph structure using ASCII art notation: <ul> <li><code>()</code> - A node</li> <li><code>(n)</code> - A node bound to variable <code>n</code></li> <li><code>(n:Label)</code> - A node with label <code>Label</code></li> <li><code>(n:Label {prop: value})</code> - A node with label and properties</li> <li><code>-[r:TYPE]-></code> - A directed relationship</li> <li><code>-[r:TYPE]-</code> - An undirected relationship</li> <li><code>-[:TYPE*1..3]-></code> - Variable-length path (1 to 3 hops)</li> </ul> <h4 id="variables-and-binding" class="position-relative d-flex align-items-center group"> Variables and Binding <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="variables-and-binding" aria-haspopup="dialog" aria-label="Share link: Variables and Binding"> Share link </button> </h4>Variables bind to matched elements, allowing you to reference them in other clauses: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">MATCH (u:User {id: $userId})-[:FOLLOWS]->(followed:User) -[:POSTED]->(post:Post) WHERE post.created > current_timestamp() - INTERVAL '7' DAY RETURN followed.username, post.content, post.created ORDER BY post.created DESC </code></pre></div>Variables scope within a query. Use <code>WITH</code> to pass variables between query parts: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">MATCH (u:User) WITH u, count{(u)-[:POSTED]->()} AS post_count WHERE post_count > 10 RETURN u.username, post_count </code></pre></div> <h3 id="basic-query-operations" class="position-relative d-flex align-items-center group"> Basic Query Operations <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-query-operations" aria-haspopup="dialog" aria-label="Share link: Basic Query Operations"> Share link </button> </h3> <h4 id="reading-data-match" class="position-relative d-flex align-items-center group"> Reading Data: MATCH <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="reading-data-match" aria-haspopup="dialog" aria-label="Share link: Reading Data: MATCH"> Share link </button> </h4><code>MATCH</code> finds patterns in the graph: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Single node MATCH (n:Person) RETURN n.name -- Node with specific properties MATCH (n:Person {country: 'USA', age: 25}) RETURN n.name -- Node with relationship MATCH (a:Person)-[:KNOWS]->(b:Person) RETURN a.name, b.name -- Multi-hop relationship MATCH (a:Person)-[:KNOWS]->(:Person)-[:KNOWS]->(c:Person) WHERE a.name = 'Alice' RETURN c.name </code></pre></div> <h4 id="creating-data-create" class="position-relative d-flex align-items-center group"> Creating Data: CREATE <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="creating-data-create" aria-haspopup="dialog" aria-label="Share link: Creating Data: CREATE"> Share link </button> </h4><code>CREATE</code> adds new nodes and relationships: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Create single node CREATE (n:Person {name: 'Alice', age: 30}) -- Create multiple nodes CREATE (a:Person {name: 'Alice'}), (b:Person {name: 'Bob'}) -- Create nodes with relationship CREATE (a:Person {name: 'Alice'}) -[:KNOWS {since: 2020}]-> (b:Person {name: 'Bob'}) </code></pre></div> <h4 id="updating-data-set-and-remove" class="position-relative d-flex align-items-center group"> Updating Data: SET and REMOVE <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="updating-data-set-and-remove" aria-haspopup="dialog" aria-label="Share link: Updating Data: SET and REMOVE"> Share link </button> </h4><code>SET</code> modifies properties: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Set single property MATCH (n:Person {name: 'Alice'}) SET n.age = 31 -- Set multiple properties MATCH (n:Person {name: 'Alice'}) SET n.age = 31, n.city = 'New York' -- Add label MATCH (n:Person {name: 'Alice'}) SET n:VIP -- Copy properties MATCH (a:Person {name: 'Alice'}), (b:Person {name: 'Bob'}) SET b = a </code></pre></div><code>REMOVE</code> deletes properties or labels: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Remove property MATCH (n:Person {name: 'Alice'}) REMOVE n.age -- Remove label MATCH (n:Person {name: 'Alice'}) REMOVE n:VIP </code></pre></div> <h4 id="deleting-data-delete" class="position-relative d-flex align-items-center group"> Deleting Data: DELETE <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="deleting-data-delete" aria-haspopup="dialog" aria-label="Share link: Deleting Data: DELETE"> Share link </button> </h4><code>DELETE</code> removes nodes and relationships: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Delete relationship MATCH (a:Person)-[r:KNOWS]->(b:Person) WHERE a.name = 'Alice' AND b.name = 'Bob' DELETE r -- Delete node and its relationships MATCH (n:Person {name: 'Alice'}) DETACH DELETE n -- Delete all matching nodes MATCH (n:TempData) DELETE n </code></pre></div><code>DETACH DELETE</code> automatically removes all relationships connected to deleted nodes. <h3 id="filtering-with-where" class="position-relative d-flex align-items-center group"> Filtering with WHERE <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="filtering-with-where" aria-haspopup="dialog" aria-label="Share link: Filtering with WHERE"> Share link </button> </h3><code>WHERE</code> filters matched patterns using predicates: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Comparison operators MATCH (n:Person) WHERE n.age > 25 AND n.age < 40 RETURN n.name -- String matching MATCH (n:Person) WHERE n.name STARTS WITH 'A' OR n.email CONTAINS '@example.com' RETURN n.name -- NULL checks MATCH (n:Person) WHERE n.middle_name IS NULL RETURN n.name -- List membership MATCH (n:Person) WHERE n.country IN ['USA', 'Canada', 'Mexico'] RETURN n.name -- Pattern existence MATCH (u:User) WHERE EXISTS { MATCH (u)-[:PURCHASED]->(:Product {category: 'Electronics'}) } RETURN u.name </code></pre></div> <h3 id="aggregations-and-grouping" class="position-relative d-flex align-items-center group"> Aggregations and Grouping <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="aggregations-and-grouping" aria-haspopup="dialog" aria-label="Share link: Aggregations and Grouping"> Share link </button> </h3>GQL provides statistical aggregation functions: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Count MATCH (n:Person) RETURN count(n) AS total_people -- Sum, average, min, max MATCH (u:User)-[t:TRANSACTION]->() RETURN u.name, sum(t.amount) AS total_spent, avg(t.amount) AS avg_transaction, min(t.amount) AS smallest, max(t.amount) AS largest -- Group by MATCH (p:Product) RETURN p.category, count(p) AS products_per_category GROUP BY p.category ORDER BY products_per_category DESC -- Collect into list MATCH (u:User {name: 'Alice'})-[:KNOWS]->(friend:Person) RETURN u.name, collect(friend.name) AS friend_names </code></pre></div> <h3 id="advanced-pattern-matching" class="position-relative d-flex align-items-center group"> Advanced Pattern Matching <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" aria-haspopup="dialog" aria-label="Share link: Advanced Pattern Matching"> Share link </button> </h3> <h4 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> </h4>Match paths with varying length: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- 1 to 3 hops MATCH (a:Person {name: 'Alice'})-[:KNOWS*1..3]->(friend:Person) RETURN friend.name -- Exactly 2 hops MATCH (a:Person {name: 'Alice'})-[:KNOWS*2]->(friend:Person) RETURN friend.name -- Any length (use cautiously!) MATCH path = (a:Person {name: 'Alice'})-[:KNOWS*]->(b:Person {name: 'Bob'}) RETURN path </code></pre></div> <h4 id="shortest-paths" class="position-relative d-flex align-items-center group"> Shortest 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="shortest-paths" aria-haspopup="dialog" aria-label="Share link: Shortest Paths"> Share link </button> </h4>Find minimal-length paths: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Shortest path MATCH path = SHORTEST (a:Person {name: 'Alice'}) -[:KNOWS*]-> (b:Person {name: 'Bob'}) RETURN path, length(path) AS hops -- All shortest paths MATCH paths = ALL SHORTEST (a:Person {name: 'Alice'}) -[:KNOWS*]-> (b:Person {name: 'Bob'}) RETURN paths </code></pre></div> <h4 id="optional-patterns" class="position-relative d-flex align-items-center group"> Optional 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="optional-patterns" aria-haspopup="dialog" aria-label="Share link: Optional Patterns"> Share link </button> </h4>Match patterns that may not exist: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- OPTIONAL MATCH returns NULL if pattern doesn't exist MATCH (u:User) OPTIONAL MATCH (u)-[:PURCHASED]->(p:Product) RETURN u.name, p.name -- Multiple optional patterns MATCH (u:User {name: 'Alice'}) OPTIONAL MATCH (u)-[:LIKES]->(post:Post) OPTIONAL MATCH (u)-[:FOLLOWS]->(other:User) RETURN u.name, post.title, other.username </code></pre></div> <h4 id="subqueries" class="position-relative d-flex align-items-center group"> Subqueries <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="subqueries" aria-haspopup="dialog" aria-label="Share link: Subqueries"> Share link </button> </h4>Execute nested queries: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Correlated subquery MATCH (u:User) WHERE EXISTS { MATCH (u)-[:PURCHASED]->(p:Product) WHERE p.price > 100 } RETURN u.name -- COUNT subquery MATCH (u:User) WITH u, count{(u)-[:POSTED]->()} AS post_count WHERE post_count > 10 RETURN u.username, post_count </code></pre></div> <h3 id="ordering-and-limiting-results" class="position-relative d-flex align-items-center group"> Ordering and Limiting 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="ordering-and-limiting-results" aria-haspopup="dialog" aria-label="Share link: Ordering and Limiting Results"> Share link </button> </h3>Control result ordering and size: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Order by single property MATCH (p:Product) RETURN p.name, p.price ORDER BY p.price DESC -- Order by multiple properties MATCH (p:Person) RETURN p.lastName, p.firstName ORDER BY p.lastName, p.firstName -- Limit results MATCH (p:Product) RETURN p.name, p.price ORDER BY p.price DESC LIMIT 10 -- Skip and limit (pagination) MATCH (p:Product) RETURN p.name, p.price ORDER BY p.price DESC SKIP 20 LIMIT 10 </code></pre></div> <h3 id="working-with-data-types" class="position-relative d-flex align-items-center group"> Working with Data 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="working-with-data-types" aria-haspopup="dialog" aria-label="Share link: Working with Data Types"> Share link </button> </h3>GQL supports rich data types: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Strings CREATE (n:Node {text: 'Hello, World!'}) -- Numbers (integers and floats) CREATE (n:Node {count: 42, ratio: 3.14159}) -- Booleans CREATE (n:Node {active: true, deleted: false}) -- Dates and times CREATE (n:Node { created: DATE '2024-01-15', updated: TIMESTAMP '2024-01-15T10:30:00Z', duration: DURATION 'P1Y2M3DT4H5M6S' }) -- Lists CREATE (n:Node {tags: ['important', 'urgent', 'review']}) -- Maps CREATE (n:Node {metadata: {author: 'Alice', version: 2}}) -- NULL values CREATE (n:Node {optional_field: NULL}) </code></pre></div> <h3 id="parameterized-queries" class="position-relative d-flex align-items-center group"> Parameterized Queries <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="parameterized-queries" aria-haspopup="dialog" aria-label="Share link: Parameterized Queries"> Share link </button> </h3>Use parameters for security and performance: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-python" data-lang="python">import geode_client client = geode_client.open_database("localhost:3141") async with client.connection() as client: result, _ = await client.query(""" MATCH (u:User {email: $email}) SET u.last_login = $timestamp RETURN u """, { "email": "[email protected]", "timestamp": datetime.now(timezone.utc) }) </code></pre></div>Parameters prevent SQL injection, enable query plan caching, and improve readability. <h3 id="transaction-control" class="position-relative d-flex align-items-center group"> Transaction Control <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="transaction-control" aria-haspopup="dialog" aria-label="Share link: Transaction Control"> Share link </button> </h3>Manage multi-statement transactions: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-python" data-lang="python">async with client.connection() as tx: await tx.begin() # All operations in one transaction await tx.execute(""" MATCH (a:Account {id: $from}) SET a.balance = a.balance - $amount """, {"from": 123, "amount": 100}) await tx.execute(""" MATCH (a:Account {id: $to}) SET a.balance = a.balance + $amount """, {"to": 456, "amount": 100}) # Commit atomically await tx.commit() </code></pre></div> <h3 id="best-practices" class="position-relative d-flex align-items-center group"> 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="best-practices" aria-haspopup="dialog" aria-label="Share link: Best Practices"> Share link </button> </h3><ol> <li>Use parameters: Never concatenate user input into queries</li> <li>Filter early: Place selective predicates in <code>MATCH</code> patterns when possible</li> <li>Limit results: Always use <code>LIMIT</code> for unbounded queries</li> <li>Index wisely: Create indexes on properties used in <code>WHERE</code> and <code>MATCH</code></li> <li>Avoid Cartesian products: Ensure patterns are connected</li> <li>Use OPTIONAL carefully: Optional matches can complicate query plans</li> <li>Profile queries: Use <code>EXPLAIN</code> and <code>PROFILE</code> to understand execution</li> <li>Document complex queries: Explain business logic in comments</li> </ol> <h3 id="common-patterns" class="position-relative d-flex align-items-center group"> Common 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="common-patterns" aria-haspopup="dialog" aria-label="Share link: Common Patterns"> Share link </button> </h3> <h4 id="recommendation-query" class="position-relative d-flex align-items-center group"> Recommendation Query <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="recommendation-query" aria-haspopup="dialog" aria-label="Share link: Recommendation Query"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Collaborative filtering MATCH (me:User {id: $userId})-[:LIKES]->(item)<-[:LIKES]-(similar:User) -[:LIKES]->(recommendation) WHERE NOT EXISTS {MATCH (me)-[:LIKES]->(recommendation)} RETURN recommendation.title, COUNT(similar) AS score ORDER BY score DESC LIMIT 10 </code></pre></div> <h4 id="fraud-detection" class="position-relative d-flex align-items-center group"> Fraud Detection <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="fraud-detection" aria-haspopup="dialog" aria-label="Share link: Fraud Detection"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Find suspicious transaction patterns MATCH (a1:Account)-[t1:TRANSFER]->(a2:Account)-[t2:TRANSFER]->(a3:Account) WHERE a3.id = a1.id AND t1.timestamp > current_timestamp() - INTERVAL '24' HOUR RETURN a1.id, a2.id, SUM(t1.amount) AS circular_flow </code></pre></div> <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">-- Find friends of friends who aren't yet friends MATCH (me:User {id: $userId})-[:FRIEND]->(friend)-[:FRIEND]->(suggestion) WHERE NOT EXISTS {MATCH (me)-[:FRIEND]->(suggestion)} AND suggestion.id <> $userId RETURN suggestion.name, COUNT(friend) AS mutual_friends ORDER BY mutual_friends DESC LIMIT 10 </code></pre></div> <h3 id="related-topics" class="position-relative d-flex align-items-center group"> Related Topics <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-topics" aria-haspopup="dialog" aria-label="Share link: Related Topics"> Share link </button> </h3><ul> <li><a href="/tags/gql-syntax/" >GQL Syntax Reference</a> - Detailed syntax documentation</li> <li><a href="/tags/pattern-matching/" >Pattern Matching</a> - Advanced pattern techniques</li> <li><a href="/categories/query-optimization/" >Query Optimization</a> - Performance tuning</li> <li><a href="/tags/functions/" >Aggregation Functions</a> - Statistical operations</li> <li><a href="/tags/iso-gql/" >ISO GQL Standard</a> - Official specification</li> <li><a href="/tags/match/" >MATCH Clause</a> - Pattern matching details</li> <li><a href="/tags/operators/" >Operators</a> - Comparison and logical operators</li> </ul> <h3 id="advanced-gql-features" class="position-relative d-flex align-items-center group"> Advanced GQL Features <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-gql-features" aria-haspopup="dialog" aria-label="Share link: Advanced GQL Features"> Share link </button> </h3> <h4 id="window-functions" class="position-relative d-flex align-items-center group"> Window 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="window-functions" aria-haspopup="dialog" aria-label="Share link: Window Functions"> Share link </button> </h4>Window functions perform calculations across sets of rows related to the current row: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Rank products within categories MATCH (p:Product) RETURN p.category, p.name, p.price, RANK() OVER (PARTITION BY p.category ORDER BY p.price DESC) AS price_rank, AVG(p.price) OVER (PARTITION BY p.category) AS category_avg_price ORDER BY p.category, price_rank </code></pre></div>Supported Window Functions: <ul> <li><code>ROW_NUMBER()</code>: Sequential number for each row</li> <li><code>RANK()</code>: Rank with gaps for ties</li> <li><code>DENSE_RANK()</code>: Rank without gaps</li> <li><code>PERCENT_RANK()</code>: Relative rank (0 to 1)</li> <li><code>NTILE(n)</code>: Divide rows into n buckets</li> <li><code>LAG(expr, offset)</code>: Access previous row</li> <li><code>LEAD(expr, offset)</code>: Access next row</li> <li><code>FIRST_VALUE(expr)</code>: First value in window</li> <li><code>LAST_VALUE(expr)</code>: Last value in window</li> </ul> <h4 id="common-table-expressions-ctes" class="position-relative d-flex align-items-center group"> Common Table Expressions (CTEs) <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="common-table-expressions-ctes" aria-haspopup="dialog" aria-label="Share link: Common Table Expressions (CTEs)"> Share link </button> </h4>CTEs create named temporary result sets for complex queries: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Find users and their influence score WITH user_metrics AS ( MATCH (u:User) RETURN u, COUNT{(u)<-[:FOLLOWS]-()} AS follower_count, COUNT{(u)-[:POSTED]->()} AS post_count ), engagement AS ( MATCH (u:User)-[:POSTED]->(p:Post) RETURN u, AVG(p.likes + p.comments) AS avg_engagement ) MATCH (u:User) WITH u, user_metrics.follower_count AS followers, user_metrics.post_count AS posts, engagement.avg_engagement AS engagement WHERE user_metrics.u = u AND engagement.u = u RETURN u.username, followers, posts, engagement, (followers * 0.4 + posts * 0.2 + engagement * 0.4) AS influence_score ORDER BY influence_score DESC LIMIT 100 </code></pre></div> <h4 id="recursive-queries" class="position-relative d-flex align-items-center group"> Recursive Queries <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="recursive-queries" aria-haspopup="dialog" aria-label="Share link: Recursive Queries"> Share link </button> </h4>Find all nodes reachable through recursive traversal: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Find all descendants in organizational hierarchy MATCH (root:Employee {name: 'CEO'}) WITH root MATCH path = (root)-[:MANAGES*0..]->(subordinate:Employee) RETURN subordinate.name, subordinate.title, LENGTH(path) AS reporting_levels ORDER BY reporting_levels, subordinate.name </code></pre></div>Depth Control: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Limit recursion depth MATCH (start:Node {id: 1})-[*1..5]->(reachable) RETURN DISTINCT reachable -- Find all reachable (use cautiously) MATCH (start:Node {id: 1})-[*]->(reachable) RETURN DISTINCT reachable </code></pre></div> <h4 id="graph-pattern-expressions" class="position-relative d-flex align-items-center group"> Graph Pattern 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="graph-pattern-expressions" aria-haspopup="dialog" aria-label="Share link: Graph Pattern Expressions"> Share link </button> </h4>Combine multiple patterns with Boolean logic: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Find users matching complex criteria MATCH (u:User) WHERE ( // Pattern 1: Active premium users (u.subscription = 'premium' AND u.last_login > current_date() - INTERVAL '7' DAY) OR // Pattern 2: High engagement free users (u.subscription = 'free' AND COUNT{(u)-[:POSTED]->()) > 50} ) AND NOT EXISTS { // Exclude suspended users MATCH (u)-[:SUSPENDED]->(s:Suspension) WHERE s.active = true } RETURN u.username, u.subscription, u.last_login </code></pre></div> <h4 id="list-comprehensions" class="position-relative d-flex align-items-center group"> List 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="list-comprehensions" aria-haspopup="dialog" aria-label="Share link: List Comprehensions"> Share link </button> </h4>Process lists with filtering and transformation: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Extract and process relationship properties MATCH (u:User {id: $user_id})-[follows:FOLLOWS]->(friend:User) RETURN u.name, [f IN COLLECT(friend) WHERE f.active = true | f.name] AS active_friends, [f IN COLLECT(follows) | f.since] AS friendship_dates, REDUCE(total = 0, f IN COLLECT(friend) | total + f.follower_count) AS total_network_reach </code></pre></div>List Functions: <ul> <li><code>COLLECT(expr)</code>: Aggregate to list</li> <li><code>HEAD(list)</code>: First element</li> <li><code>TAIL(list)</code>: All but first</li> <li><code>LAST(list)</code>: Last element</li> <li><code>SIZE(list)</code>: List length</li> <li><code>REVERSE(list)</code>: Reverse order</li> <li><code>REDUCE(...)</code>: Fold/reduce operation</li> </ul> <h4 id="map-projections" class="position-relative d-flex align-items-center group"> Map Projections <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-projections" aria-haspopup="dialog" aria-label="Share link: Map Projections"> Share link </button> </h4>Create maps from node properties: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Return structured data MATCH (u:User {id: $user_id}) RETURN { user: { id: u.id, name: u.name, email: u.email }, stats: { follower_count: COUNT{(u)<-[:FOLLOWS]-()}, following_count: COUNT{(u)-[:FOLLOWS]->()}, post_count: COUNT{(u)-[:POSTED]->()} }, recent_activity: [ (u)-[:POSTED]->(p:Post) WHERE p.created > current_date() - INTERVAL '7' DAY | {title: p.title, created: p.created, likes: p.likes} ] } AS user_profile </code></pre></div> <h3 id="query-optimization-techniques" class="position-relative d-flex align-items-center group"> Query Optimization Techniques <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="query-optimization-techniques" aria-haspopup="dialog" aria-label="Share link: Query Optimization Techniques"> Share link </button> </h3> <h4 id="index-hints" class="position-relative d-flex align-items-center group"> Index Hints <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="index-hints" aria-haspopup="dialog" aria-label="Share link: Index Hints"> Share link </button> </h4>Guide the query planner to use specific indexes: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Force index usage MATCH (u:User) USING INDEX u:User(email) WHERE u.email = $email RETURN u -- Scan hint for small result sets MATCH (u:User) USING SCAN u:User WHERE u.role = 'admin' RETURN u </code></pre></div> <h4 id="join-hints" class="position-relative d-flex align-items-center group"> Join Hints <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="join-hints" aria-haspopup="dialog" aria-label="Share link: Join Hints"> Share link </button> </h4>Control join strategy: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Force hash join MATCH (a:User)-[:FRIEND]-(b:User) OPTION (join=hash) WHERE a.city = 'NYC' AND b.city = 'SF' RETURN a.name, b.name -- Force nested loop MATCH (a:User)-[:FRIEND]-(b:User) OPTION (join=nested_loop) WHERE a.id = $user_id RETURN b.name </code></pre></div> <h4 id="query-rewriting" class="position-relative d-flex align-items-center group"> Query Rewriting <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="query-rewriting" aria-haspopup="dialog" aria-label="Share link: Query Rewriting"> Share link </button> </h4>Before optimization: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Inefficient: Cartesian product MATCH (u:User), (p:Product) WHERE u.city = p.warehouse_city RETURN u.name, p.name </code></pre></div>After optimization: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Efficient: Explicit relationship or property join MATCH (u:User) MATCH (p:Product {warehouse_city: u.city}) RETURN u.name, p.name </code></pre></div> <h4 id="projection-pushdown" class="position-relative d-flex align-items-center group"> Projection Pushdown <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="projection-pushdown" aria-haspopup="dialog" aria-label="Share link: Projection Pushdown"> Share link </button> </h4>Select only needed columns early: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Inefficient: Materializes all properties MATCH (u:User)-[:POSTED]->(p:Post) WITH u, p WHERE p.likes > 100 RETURN u.name, p.title -- Efficient: Project early MATCH (u:User)-[:POSTED]->(p:Post) WHERE p.likes > 100 RETURN u.name, p.title </code></pre></div> <h3 id="functions-and-operators" class="position-relative d-flex align-items-center group"> Functions and Operators <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="functions-and-operators" aria-haspopup="dialog" aria-label="Share link: Functions and Operators"> Share link </button> </h3> <h4 id="string-functions" class="position-relative d-flex align-items-center group"> String 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="string-functions" aria-haspopup="dialog" aria-label="Share link: String Functions"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- String manipulation MATCH (u:User) WHERE toLower(u.name) CONTAINS 'alice' RETURN u.name, toUpper(u.email) AS email_upper, substring(u.email, 0, indexOf(u.email, '@')) AS email_prefix, replace(u.phone, '-', '') AS phone_clean, trim(u.address) AS address_trimmed, left(u.postal_code, 5) AS zip5, right(u.postal_code, 4) AS zip4_extension </code></pre></div> <h4 id="mathematical-functions" class="position-relative d-flex align-items-center group"> Mathematical 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="mathematical-functions" aria-haspopup="dialog" aria-label="Share link: Mathematical Functions"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Math operations MATCH (product:Product) RETURN product.name, product.price, round(product.price * 1.08, 2) AS price_with_tax, floor(product.price) AS price_floor, ceil(product.price) AS price_ceil, abs(product.profit_margin) AS abs_margin, sqrt(product.variance) AS std_deviation, power(product.growth_rate, 12) AS annual_growth </code></pre></div> <h4 id="temporal-functions" class="position-relative d-flex align-items-center group"> Temporal 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="temporal-functions" aria-haspopup="dialog" aria-label="Share link: Temporal Functions"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Date and time operations MATCH (event:Event) WHERE event.date >= date('2026-01-01') AND event.date < date('2026-02-01') RETURN event.name, event.date, duration_between(event.start_time, event.end_time) AS event_duration, date_add(event.date, duration('P7D')) AS week_later, extract(month FROM event.date) AS event_month, extract(year FROM event.date) AS event_year, format_temporal(event.date, 'YYYY-MM-DD') AS formatted_date </code></pre></div> <h4 id="aggregation-functions" class="position-relative d-flex align-items-center group"> Aggregation 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="aggregation-functions" aria-haspopup="dialog" aria-label="Share link: Aggregation Functions"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Statistical aggregations MATCH (product:Product)-[:IN_CATEGORY]->(category:Category) RETURN category.name, COUNT(product) AS product_count, MIN(product.price) AS min_price, MAX(product.price) AS max_price, AVG(product.price) AS avg_price, SUM(product.inventory) AS total_inventory, STDDEV(product.price) AS price_stddev, VARIANCE(product.price) AS price_variance, PERCENTILE_CONT(product.price, 0.5) AS median_price, PERCENTILE_CONT(product.price, 0.95) AS p95_price </code></pre></div> <h4 id="graph-functions" class="position-relative d-flex align-items-center group"> Graph 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="graph-functions" aria-haspopup="dialog" aria-label="Share link: Graph Functions"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Graph-specific functions MATCH path = (a:Person {name: 'Alice'})-[:KNOWS*1..5]-(b:Person {name: 'Bob'}) RETURN path, LENGTH(path) AS path_length, nodes(path) AS all_nodes, relationships(path) AS all_relationships, [n IN nodes(path) | n.name] AS node_names, [r IN relationships(path) | type(r)] AS relationship_types, SIZE(nodes(path)) AS node_count </code></pre></div> <h3 id="error-handling-in-queries" class="position-relative d-flex align-items-center group"> Error Handling in Queries <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="error-handling-in-queries" aria-haspopup="dialog" aria-label="Share link: Error Handling in Queries"> Share link </button> </h3> <h4 id="coalesce-for-null-handling" class="position-relative d-flex align-items-center group"> COALESCE for Null Handling <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="coalesce-for-null-handling" aria-haspopup="dialog" aria-label="Share link: COALESCE for Null Handling"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Provide defaults for null values MATCH (u:User) RETURN u.name, COALESCE(u.middle_name, '') AS middle_name, COALESCE(u.phone, 'No phone') AS contact, COALESCE(u.age, 0) AS age </code></pre></div> <h4 id="case-expressions" class="position-relative d-flex align-items-center group"> CASE 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="case-expressions" aria-haspopup="dialog" aria-label="Share link: CASE Expressions"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Conditional logic MATCH (product:Product) RETURN product.name, product.inventory, CASE WHEN product.inventory = 0 THEN 'Out of Stock' WHEN product.inventory < 10 THEN 'Low Stock' WHEN product.inventory < 50 THEN 'In Stock' ELSE 'Well Stocked' END AS stock_status, CASE product.category WHEN 'Electronics' THEN product.price * 0.9 WHEN 'Clothing' THEN product.price * 0.8 ELSE product.price * 0.95 END AS sale_price </code></pre></div> <h4 id="try-catch-pattern" class="position-relative d-flex align-items-center group"> TRY-CATCH 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="try-catch-pattern" aria-haspopup="dialog" aria-label="Share link: TRY-CATCH Pattern"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-python" data-lang="python"># Application-level error handling async def safe_query_execution(client, query, params): """Execute query with comprehensive error handling.""" try: result, _ = await client.query(query, params) return result except geode_client.ConstraintViolationError as e: logger.error(f"Constraint violation: {e}") # Handle uniqueness or other constraint issues return None except geode_client.QueryTimeoutError as e: logger.warning(f"Query timeout: {e}") # Potentially retry with increased timeout return None except geode_client.SyntaxError as e: logger.error(f"Invalid query syntax: {e}") # Fix query and retry return None except Exception as e: logger.exception(f"Unexpected error: {e}") raise </code></pre></div> <h3 id="query-performance-patterns" class="position-relative d-flex align-items-center group"> Query Performance 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="query-performance-patterns" aria-haspopup="dialog" aria-label="Share link: Query Performance Patterns"> Share link </button> </h3> <h4 id="batch-operations" class="position-relative d-flex align-items-center group"> Batch Operations <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="batch-operations" aria-haspopup="dialog" aria-label="Share link: Batch Operations"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Batch inserts for efficiency UNWIND $users AS user_data CREATE (u:User) SET u = user_data -- Batch updates UNWIND $updates AS update MATCH (u:User {id: update.id}) SET u.last_login = update.timestamp </code></pre></div> <h4 id="pagination-strategies" class="position-relative d-flex align-items-center group"> Pagination Strategies <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="pagination-strategies" aria-haspopup="dialog" aria-label="Share link: Pagination Strategies"> Share link </button> </h4>Offset-based pagination (simple but slower for large offsets): <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">MATCH (p:Product) RETURN p ORDER BY p.created DESC SKIP $offset LIMIT $page_size </code></pre></div>Cursor-based pagination (efficient for large datasets): <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- First page MATCH (p:Product) WHERE p.id > 0 RETURN p ORDER BY p.id LIMIT $page_size -- Subsequent pages MATCH (p:Product) WHERE p.id > $last_seen_id RETURN p ORDER BY p.id LIMIT $page_size </code></pre></div> <h4 id="materialized-aggregates" class="position-relative d-flex align-items-center group"> Materialized Aggregates <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="materialized-aggregates" aria-haspopup="dialog" aria-label="Share link: Materialized Aggregates"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Pre-compute expensive aggregates MATCH (user:User) WITH user, COUNT{(user)-[:POSTED]->()} AS post_count, COUNT{(user)<-[:FOLLOWS]-()} AS follower_count SET user.cached_post_count = post_count, user.cached_follower_count = follower_count, user.cache_updated = current_timestamp() -- Use cached values in queries MATCH (u:User) WHERE u.cached_follower_count > 1000 RETURN u.name, u.cached_follower_count </code></pre></div> <h3 id="security-best-practices" class="position-relative d-flex align-items-center group"> Security 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="security-best-practices" aria-haspopup="dialog" aria-label="Share link: Security Best Practices"> Share link </button> </h3> <h4 id="parameterized-queries-1" class="position-relative d-flex align-items-center group"> Parameterized Queries <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="parameterized-queries-1" aria-haspopup="dialog" aria-label="Share link: Parameterized Queries"> Share link </button> </h4>Never concatenate user input: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-python" data-lang="python"># WRONG - SQL injection vulnerable user_input = request.args.get('email') query = f"MATCH (u:User {{email: '{user_input}'}}) RETURN u" # CORRECT - Parameterized query = "MATCH (u:User {email: $email}) RETURN u" result, _ = await client.query(query, {"email": user_input}) </code></pre></div> <h4 id="input-validation" class="position-relative d-flex align-items-center group"> Input Validation <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="input-validation" aria-haspopup="dialog" aria-label="Share link: Input Validation"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-python" data-lang="python">def validate_query_params(params: dict) -> dict: """Validate and sanitize query parameters.""" validated = {} if 'email' in params: email = params['email'] if not re.match(r'^[\w\.-]+@[\w\.-]+\.\w+$', email): raise ValueError("Invalid email format") validated['email'] = email if 'age' in params: age = int(params['age']) if age < 0 or age > 150: raise ValueError("Invalid age") validated['age'] = age return validated </code></pre></div> <h3 id="query-debugging-tools" class="position-relative d-flex align-items-center group"> Query Debugging Tools <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="query-debugging-tools" aria-haspopup="dialog" aria-label="Share link: Query Debugging Tools"> Share link </button> </h3> <h4 id="explain-plans" class="position-relative d-flex align-items-center group"> EXPLAIN Plans <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="explain-plans" aria-haspopup="dialog" aria-label="Share link: EXPLAIN Plans"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- View query execution plan EXPLAIN MATCH (u:User)-[:FRIEND]-(f:User) WHERE u.city = 'NYC' RETURN f.name -- Example output: -- NodeIndexSeek :User(city) (estimated rows: 1000) -- Expand (u)-[:FRIEND]-(f) -- Project f.name </code></pre></div> <h4 id="profile-for-actual-execution" class="position-relative d-flex align-items-center group"> PROFILE for Actual Execution <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="profile-for-actual-execution" aria-haspopup="dialog" aria-label="Share link: PROFILE for Actual Execution"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Profile actual execution with real data PROFILE MATCH (u:User)-[:FRIEND]-(f:User) WHERE u.city = 'NYC' RETURN f.name -- Shows actual row counts, execution time, memory usage </code></pre></div> <h3 id="further-reading" class="position-relative d-flex align-items-center group"> Further Reading <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="further-reading" aria-haspopup="dialog" aria-label="Share link: Further Reading"> Share link </button> </h3><ul> <li><a href="/docs/gql-tutorial/" >GQL Tutorial</a> - Step-by-step learning path</li> <li><a href="/docs/api-reference/" >API Reference</a> - Complete function reference</li> <li><a href="/categories/examples/" >Examples</a> - Real-world query examples</li> <li><a href="/docs/gql-reference/specification/" >GQL Specification</a> - ISO standard details</li> <li><a href="/docs/query/performance-tuning/" >Query Optimization Guide</a> - Performance tuning</li> <li><a href="/docs/gql-reference/advanced-patterns/" >Advanced Patterns</a> - Complex query techniques</li> <li><a href="/docs/gql-reference/functions/" >Function Reference</a> - Complete function catalog</li> <li><a href="/categories/best-practices/" >Best Practices</a> - Query writing guidelines</li> </ul>

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