Code Examples

<h2 id="code-examples" class="position-relative d-flex align-items-center group"> Code 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="code-examples" aria-haspopup="dialog" aria-label="Share link: Code Examples"> 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; letter-spacing: 0.5px;">Share via</div> <div class="hsm-share-grid"> <a id="share-twitter" class="btn btn-outline-secondary w-100" target="_blank" rel="noopener noreferrer"> Twitter </a> <a id="share-linkedin" class="btn btn-outline-secondary w-100" target="_blank" rel="noopener noreferrer"> LinkedIn </a> <a id="share-facebook" class="btn btn-outline-secondary w-100" target="_blank" rel="noopener noreferrer"> Facebook </a> </div> </div> </div> </div> <style> .heading-share-modal { position: fixed; inset: 0; display: flex; justify-content: center; align-items: center; background: rgba(0, 0, 0, 0.6); z-index: 1050; padding: 1rem; backdrop-filter: blur(4px); -webkit-backdrop-filter: blur(4px); } .heading-share-modal[hidden] { display: none !important; } .hsm-dialog { max-width: 420px; width: 100%; background: var(--bs-body-bg, #fff); color: var(--bs-body-color, #212529); border: 1px solid var(--bs-border-color, rgba(0,0,0,0.1)); border-radius: 1rem; box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25); 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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>Code examples provide immediate, practical demonstrations of Geode features through working code snippets. Unlike tutorials that explain concepts step-by-step, examples show you exactly how to accomplish specific tasks with copy-paste-ready code in Python, Go, Rust, and Zig. <h3 id="why-code-examples-matter" class="position-relative d-flex align-items-center group"> Why Code Examples Matter <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="why-code-examples-matter" aria-haspopup="dialog" aria-label="Share link: Why Code Examples Matter"> Share link </button> </h3>Immediate Understanding: See how a feature works in seconds rather than reading lengthy explanations. Examples answer “show me how” more effectively than prose descriptions. Language-Specific Patterns: Each language has idiomatic approaches to database integration. Examples demonstrate best practices for your preferred ecosystem—async/await in Python, database/sql in Go, tokio in Rust, or manual memory management in Zig. Real-World Context: Examples use realistic scenarios—user authentication, product recommendations, social graphs, fraud detection—helping you understand how features apply to actual problems. Executable Code: Every example is tested and runnable. Copy the code into your project and it works, accelerating development from prototype to production. <h3 id="example-categories" class="position-relative d-flex align-items-center group"> Example Categories <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="example-categories" aria-haspopup="dialog" aria-label="Share link: Example Categories"> Share link </button> </h3> <h4 id="basic-crud-operations" class="position-relative d-flex align-items-center group"> Basic CRUD 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-crud-operations" aria-haspopup="dialog" aria-label="Share link: Basic CRUD Operations"> Share link </button> </h4>Creating Nodes: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-python" data-lang="python"># Python: Create a user node client = Client(host="localhost", port=3141) async with client.connection() as conn: result, _ = await conn.query(""" CREATE (u:User { id: $id, name: $name, email: $email, created_at: $timestamp }) RETURN u """, id="user123", name="Alice", email="[email protected]", timestamp="2025-01-24T10:00:00Z") </code></pre></div><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-go" data-lang="go">// Go: Create a product node db, _ := sql.Open("geode", "quic://localhost:3141") result, err := db.Exec(` CREATE (p:Product { id: $id, name: $name, price: $price, in_stock: $stock }) `, sql.Named("id", "prod456"), sql.Named("name", "Widget"), sql.Named("price", 29.99), sql.Named("stock", true)) </code></pre></div><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-rust" data-lang="rust">// Rust: Create a post node let client = Client::connect("localhost:3141").await?; client.execute( "CREATE (p:Post {id: $id, title: $title, content: $content})", params! { "id" => "post789", "title" => "Hello Graph", "content" => "Learning Geode is fun!" } ).await?; </code></pre></div>Reading Nodes: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-python" data-lang="python"># Python: Find user by email result, _ = await client.query( "MATCH (u:User {email: $email}) RETURN u", email="[email protected]" ) user = await result.first() print(f"Found user: {user['u']['name']}") </code></pre></div>Updating Properties: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-python" data-lang="python"># Python: Update user's last login time await client.execute(""" MATCH (u:User {id: $user_id}) SET u.last_login = $timestamp """, user_id="user123", timestamp="2025-01-24T15:30:00Z") </code></pre></div>Deleting Nodes: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-python" data-lang="python"># Python: Delete a product and its relationships await client.execute(""" MATCH (p:Product {id: $product_id}) DETACH DELETE p """, product_id="prod456") </code></pre></div> <h4 id="relationship-examples" class="position-relative d-flex align-items-center group"> Relationship 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="relationship-examples" aria-haspopup="dialog" aria-label="Share link: Relationship Examples"> Share link </button> </h4>Creating Relationships: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-python" data-lang="python"># Python: User follows another user await client.execute(""" MATCH (a:User {id: $follower_id}) MATCH (b:User {id: $followee_id}) CREATE (a)-[:FOLLOWS {since: $timestamp}]->(b) """, follower_id="user123", followee_id="user456", timestamp="2025-01-24T10:00:00Z") </code></pre></div><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-go" data-lang="go">// Go: User purchases product db.Exec(` MATCH (u:User {id: $user_id}) MATCH (p:Product {id: $product_id}) CREATE (u)-[:PURCHASED { at: $timestamp, quantity: $qty, total: $total }]->(p) `, sql.Named("user_id", "user123"), sql.Named("product_id", "prod456"), sql.Named("timestamp", time.Now()), sql.Named("qty", 2), sql.Named("total", 59.98)) </code></pre></div>Querying Relationships: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-python" data-lang="python"># Python: Find all products a user purchased result, _ = await client.query(""" MATCH (u:User {id: $user_id})-[r:PURCHASED]->(p:Product) RETURN p.name, r.quantity, r.total, r.at ORDER BY r.at DESC """, user_id="user123") for row in result.rows: print(f"{row['p.name']}: {row['r.quantity']} @ ${row['r.total']}") </code></pre></div> <h4 id="pattern-matching-examples" class="position-relative d-flex align-items-center group"> Pattern Matching 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="pattern-matching-examples" aria-haspopup="dialog" aria-label="Share link: Pattern Matching Examples"> Share link </button> </h4>Multi-Hop Traversals: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-python" data-lang="python"># Python: Friends of friends (2 degrees of separation) result, _ = await client.query(""" MATCH (me:User {id: $my_id})-[:FRIENDS*2]->(friend_of_friend) WHERE NOT EXISTS { MATCH (me)-[:FRIENDS]->(friend_of_friend) } RETURN DISTINCT friend_of_friend.name, friend_of_friend.email LIMIT 10 """, my_id="user123") </code></pre></div><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-rust" data-lang="rust">// Rust: Product recommendation via similarity let results = client.execute( r#" MATCH (u:User {id: $user_id})-[:PURCHASED]->(p:Product) -[:SIMILAR_TO]->(rec:Product) WHERE NOT EXISTS { MATCH (u)-[:PURCHASED]->(rec) } RETURN rec.name, rec.price, COUNT(*) as relevance ORDER BY relevance DESC LIMIT 5 "#, params! { "user_id" => "user123" } ).await?; </code></pre></div>Optional Patterns: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-python" data-lang="python"># Python: Users with optional profile pictures result, _ = await client.query(""" MATCH (u:User) OPTIONAL MATCH (u)-[:HAS_AVATAR]->(img:Image) RETURN u.name, u.email, img.url """) for row in result.rows: avatar = row['img.url'] if row['img.url'] else "default.png" print(f"{row['u.name']}: {avatar}") </code></pre></div> <h4 id="transaction-examples" class="position-relative d-flex align-items-center group"> Transaction 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="transaction-examples" aria-haspopup="dialog" aria-label="Share link: Transaction Examples"> Share link </button> </h4>Basic Transaction: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-python" data-lang="python"># Python: Transfer credits between users atomically async with client.connection() as tx: await tx.begin() # Deduct from sender await tx.execute(""" MATCH (sender:User {id: $sender_id}) SET sender.credits = sender.credits - $amount """, sender_id="user123", amount=100) # Add to receiver await tx.execute(""" MATCH (receiver:User {id: $receiver_id}) SET receiver.credits = receiver.credits + $amount """, receiver_id="user456", amount=100) # Both operations succeed or both fail </code></pre></div><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-go" data-lang="go">// Go: Multi-step order creation with rollback tx, _ := db.Begin() defer func() { if r := recover(); r != nil { tx.Rollback() } }() // Create order tx.Exec(`CREATE (o:Order {id: $id, user_id: $user_id, total: $total})`, sql.Named("id", orderID), sql.Named("user_id", userID), sql.Named("total", total)) // Add order items for _, item := range items { tx.Exec(` MATCH (o:Order {id: $order_id}) MATCH (p:Product {id: $product_id}) CREATE (o)-[:CONTAINS {quantity: $qty}]->(p) `, sql.Named("order_id", orderID), sql.Named("product_id", item.ProductID), sql.Named("qty", item.Quantity)) } tx.Commit() </code></pre></div>Savepoints: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-python" data-lang="python"># Python: Complex operation with partial rollback async with client.connection() as tx: await tx.begin() await tx.execute("CREATE (u:User {id: 'temp1', name: 'Test'})") savepoint = await tx.savepoint("before_optional") try: # Risky operation that might fail await tx.execute("CREATE (u:User {id: 'temp1'})") # Duplicate! except Exception: # Roll back to savepoint, keep first user await tx.rollback_to(savepoint) await tx.execute("CREATE (u:User {id: 'temp2', name: 'Test2'})") # Commits temp1 and temp2, but not the duplicate attempt </code></pre></div> <h4 id="aggregation-examples" class="position-relative d-flex align-items-center group"> Aggregation 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="aggregation-examples" aria-haspopup="dialog" aria-label="Share link: Aggregation Examples"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-python" data-lang="python"># Python: Count users by country result, _ = await client.query(""" MATCH (u:User) RETURN u.country, COUNT(*) as user_count ORDER BY user_count DESC """) </code></pre></div><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-go" data-lang="go">// Go: Average order value by month rows, _ := db.Query(` MATCH (o:Order) RETURN substring(o.created_at, 0, 7) as month, AVG(o.total) as avg_value, SUM(o.total) as total_revenue, COUNT(*) as order_count ORDER BY month DESC `) </code></pre></div><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-rust" data-lang="rust">// Rust: Top products by revenue let results = client.execute( r#" MATCH (o:Order)-[c:CONTAINS]->(p:Product) RETURN p.name, SUM(c.quantity) as units_sold, SUM(c.quantity * p.price) as revenue ORDER BY revenue DESC LIMIT 10 "#, params! {} ).await?; </code></pre></div> <h4 id="advanced-query-examples" class="position-relative d-flex align-items-center group"> Advanced Query 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="advanced-query-examples" aria-haspopup="dialog" aria-label="Share link: Advanced Query Examples"> Share link </button> </h4>Subqueries: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-python" data-lang="python"># Python: Users who purchased all items in a category result, _ = await client.query(""" MATCH (category:Category {name: $category_name})<-[:IN_CATEGORY]-(p:Product) WITH category, COUNT(p) as total_products MATCH (u:User) WHERE EXISTS { MATCH (u)-[:PURCHASED]->(p2:Product)-[:IN_CATEGORY]->(category) WITH category, COUNT(DISTINCT p2) as user_purchased WHERE user_purchased = total_products } RETURN u.name, u.email """, category_name="Electronics") </code></pre></div>Shortest Path: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-python" data-lang="python"># Python: Find shortest connection between two users result, _ = await client.query(""" MATCH path = shortestPath( (a:User {id: $user_a})-[:KNOWS*]-(b:User {id: $user_b}) ) RETURN [node IN nodes(path) | node.name] as connection_path, length(path) as degrees_of_separation """, user_a="user123", user_b="user789") </code></pre></div> <h4 id="client-specific-patterns" class="position-relative d-flex align-items-center group"> Client-Specific 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="client-specific-patterns" aria-haspopup="dialog" aria-label="Share link: Client-Specific Patterns"> Share link </button> </h4>Python Async Patterns: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-python" data-lang="python"># Concurrent queries with asyncio import asyncio async def fetch_user_data(user_id): client = Client(host="localhost", port=3141) async with client.connection() as conn: user, posts, friends = await asyncio.gather( conn.execute("MATCH (u:User {id: $id}) RETURN u", id=user_id), conn.execute("MATCH (u:User {id: $id})-[:WROTE]->(p) RETURN p", id=user_id), conn.execute("MATCH (u:User {id: $id})-[:FRIENDS]->(f) RETURN f", id=user_id) ) return user, posts, friends </code></pre></div>Go Connection Pooling: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-go" data-lang="go">// Configure connection pool db, _ := sql.Open("geode", "quic://localhost:3141") db.SetMaxOpenConns(100) db.SetMaxIdleConns(10) db.SetConnMaxLifetime(time.Hour) // Use connection from pool ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second) defer cancel() row := db.QueryRowContext(ctx, "MATCH (u:User {id: $id}) RETURN u", sql.Named("id", "user123")) </code></pre></div>Rust Stream Processing: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-rust" data-lang="rust">// Process large result sets efficiently let mut stream = client.execute( "MATCH (u:User) WHERE u.active = true RETURN u", params! {} ).stream().await?; while let Some(row) = stream.next().await { let user_id: String = row.get("u.id")?; let user_name: String = row.get("u.name")?; // Process each user without loading entire result set into memory process_user(user_id, user_name).await?; } </code></pre></div> <h4 id="error-handling-examples" class="position-relative d-flex align-items-center group"> Error Handling 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="error-handling-examples" aria-haspopup="dialog" aria-label="Share link: Error Handling Examples"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-python" data-lang="python"># Python: Retry logic for transient failures from tenacity import retry, stop_after_attempt, wait_exponential from geode_client import QueryError @retry(stop=stop_after_attempt(3), wait=wait_exponential(multiplier=1, min=1, max=10)) async def execute_with_retry(client, query, **params): try: result, _ = await client.query(query, params) return result except QueryError as exc: message = str(exc).lower() if "40502" in message: # Let retry decorator handle conflicts raise if "syntax" in message: logger.error(f"Non-retryable error: {exc}") raise raise </code></pre></div><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-go" data-lang="go">// Go: Graceful error handling row := db.QueryRow("MATCH (u:User {id: $id}) RETURN u", sql.Named("id", userID)) var user User err := row.Scan(&user.ID, &user.Name, &user.Email) if err == sql.ErrNoRows { // User not found - expected case return nil, ErrUserNotFound } else if err != nil { // Unexpected database error log.Printf("Database error: %v", err) return nil, err } </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>Tutorials: Step-by-step learning paths with explanations</li> <li>Guides: Architectural patterns and design principles</li> <li>Getting Started: Quick examples for beginners</li> <li>Developer Guide: Complete API reference and documentation</li> </ul> <h3 id="production-code-examples" class="position-relative d-flex align-items-center group"> Production Code 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="production-code-examples" aria-haspopup="dialog" aria-label="Share link: Production Code Examples"> Share link </button> </h3> <h4 id="full-stack-application-integration" class="position-relative d-flex align-items-center group"> Full-Stack Application Integration <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="full-stack-application-integration" aria-haspopup="dialog" aria-label="Share link: Full-Stack Application Integration"> Share link </button> </h4>Complete application with Geode backend: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-python" data-lang="python"># FastAPI application with Geode from fastapi import FastAPI, HTTPException, Depends, Header from geode_client import Client from pydantic import BaseModel, EmailStr import asyncio app = FastAPI() # Connection pool (reused across requests) geode_pool = Client( "localhost:3141", pool_size=20, pool_timeout=30.0 ) class UserRegistration(BaseModel): name: str email: EmailStr password: str @app.on_event("startup") async def startup(): """Initialize database connection""" await geode_pool.connect() @app.on_event("shutdown") async def shutdown(): """Close database connection""" await geode_pool.close() async def get_current_user(authorization: str = Header(...)): """Dependency: Extract user from JWT token""" token = authorization.replace("Bearer ", "") user_id = decode_jwt(token) result, _ = await geode_pool.query(""" MATCH (u:User {id: $id}) RETURN u """, {"id": user_id}) if not result: raise HTTPException(401, "Invalid token") return result.rows[0]['u'] @app.post("/api/register") async def register(user: UserRegistration): """Register new user""" # Hash password password_hash = hash_password(user.password) try: result, _ = await geode_pool.query(""" CREATE (u:User { id: randomUUID(), name: $name, email: $email, password_hash: $password_hash, created_at: datetime(), verified: false }) RETURN u.id as user_id, u.email as email """, { "name": user.name, "email": user.email, "password_hash": password_hash }) user_id = result.rows[0]['user_id'] # Send verification email await send_verification_email(user.email, user_id) return {"user_id": user_id, "message": "Registration successful"} except UniqueConstraintViolation: raise HTTPException(400, "Email already registered") @app.get("/api/users/{user_id}/profile") async def get_profile(user_id: str, current_user=Depends(get_current_user)): """Get user profile""" result, _ = await geode_pool.query(""" MATCH (u:User {id: $id}) OPTIONAL MATCH (u)-[:FRIENDS_WITH]-(friend:User) OPTIONAL MATCH (u)-[:POSTED]->(post:Post) RETURN u.id as id, u.name as name, u.email as email, u.created_at as created_at, COUNT(DISTINCT friend) as friend_count, COUNT(DISTINCT post) as post_count """, {"id": user_id}) if not result: raise HTTPException(404, "User not found") return result.rows[0] @app.post("/api/posts") async def create_post( content: str, current_user=Depends(get_current_user) ): """Create new post""" result, _ = await geode_pool.query(""" MATCH (u:User {id: $user_id}) CREATE (p:Post { id: randomUUID(), content: $content, created_at: datetime(), likes: 0, comments: 0 }) CREATE (u)-[:POSTED]->(p) RETURN p.id as post_id """, { "user_id": current_user['id'], "content": content }) return {"post_id": result.rows[0]['post_id']} @app.get("/api/feed") async def get_feed( limit: int = 20, offset: int = 0, current_user=Depends(get_current_user) ): """Get personalized feed""" result, _ = await geode_pool.query(""" MATCH (me:User {id: $user_id})-[:FRIENDS_WITH]-(friend:User)-[:POSTED]->(post:Post) WITH post, friend ORDER BY post.created_at DESC SKIP $offset LIMIT $limit RETURN post.id as id, post.content as content, post.created_at as created_at, post.likes as likes, friend.id as author_id, friend.name as author_name """, { "user_id": current_user['id'], "offset": offset, "limit": limit }) return {"posts": [dict(r) for r in result]} </code></pre></div> <h4 id="recommendation-engine" class="position-relative d-flex align-items-center group"> Recommendation Engine <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-engine" aria-haspopup="dialog" aria-label="Share link: Recommendation Engine"> Share link </button> </h4>Collaborative filtering implementation: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-python" data-lang="python">class RecommendationEngine: def __init__(self, client): self.client = client async def get_product_recommendations(self, user_id, limit=10): """Generate product recommendations using collaborative filtering""" # Find similar users based on purchase history similar_users, _ = await self.client.query(""" MATCH (me:User {id: $user_id})-[:PURCHASED]->(p:Product) <-[:PURCHASED]-(other:User) WHERE other.id <> $user_id WITH other, COUNT(p) as common_purchases, me ORDER BY common_purchases DESC LIMIT 50 MATCH (other)-[:PURCHASED]->(rec:Product) WHERE NOT EXISTS { MATCH (me)-[:PURCHASED]->(rec) } WITH rec, COUNT(other) as score, SUM(common_purchases) as weight RETURN rec.id as product_id, rec.name as name, rec.price as price, score * weight as recommendation_score ORDER BY recommendation_score DESC LIMIT $limit """, {"user_id": user_id, "limit": limit}) return similar_users async def get_content_based_recommendations(self, user_id, limit=10): """Content-based recommendations using product attributes""" recommendations, _ = await self.client.query(""" MATCH (u:User {id: $user_id})-[:PURCHASED]->(liked:Product) WITH u, COLLECT(liked.category) as liked_categories, AVG(liked.price) as avg_price MATCH (rec:Product) WHERE rec.category IN liked_categories AND NOT EXISTS { MATCH (u)-[:PURCHASED]->(rec) } AND rec.price BETWEEN avg_price * 0.7 AND avg_price * 1.3 WITH rec, SIZE([cat IN rec.tags WHERE cat IN liked_categories]) as tag_match RETURN rec.id as product_id, rec.name as name, rec.price as price, tag_match as relevance_score ORDER BY relevance_score DESC LIMIT $limit """, {"user_id": user_id, "limit": limit}) return recommendations </code></pre></div> <h4 id="social-network-analytics" class="position-relative d-flex align-items-center group"> Social Network Analytics <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-analytics" aria-haspopup="dialog" aria-label="Share link: Social Network Analytics"> Share link </button> </h4>Graph analytics for social features: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-python" data-lang="python">class SocialAnalytics: def __init__(self, client): self.client = client async def calculate_user_influence(self, user_id): """Calculate user influence score""" metrics, _ = await self.client.query(""" MATCH (u:User {id: $user_id}) OPTIONAL MATCH (u)<-[:FOLLOWS]-(follower:User) WITH u, COUNT(DISTINCT follower) as followers OPTIONAL MATCH (u)-[:POSTED]->(post:Post)<-[:LIKED]-(liker:User) WITH u, followers, COUNT(DISTINCT liker) as total_likes OPTIONAL MATCH (u)-[:POSTED]->(post:Post) WITH u, followers, total_likes, COUNT(DISTINCT post) as posts RETURN followers, total_likes, posts, (followers * 2.0 + total_likes * 0.5 + posts * 1.0) as influence_score """, {"user_id": user_id}) return metrics[0] if metrics else None async def detect_communities(self): """Detect communities using label propagation""" # Initialize communities await self.client.execute(""" MATCH (u:User) SET u.community = u.id """) # Iterate label propagation for iteration in range(10): changes, _ = await self.client.query(""" MATCH (u:User)-[:FRIENDS_WITH]-(neighbor:User) WITH u, neighbor.community as label, COUNT(*) as freq ORDER BY u, freq DESC WITH u, COLLECT(label)[0] as most_common WHERE u.community <> most_common SET u.community = most_common RETURN COUNT(u) as changes """) if changes[0]['changes'] == 0: break # Return communities communities, _ = await self.client.query(""" MATCH (u:User) RETURN u.community as community_id, COUNT(u) as size ORDER BY size DESC """) return communities async def find_influencers(self, limit=20): """Find top influencers""" influencers, _ = await self.client.query(""" MATCH (u:User) OPTIONAL MATCH (u)<-[:FOLLOWS]-(follower:User) WITH u, COUNT(DISTINCT follower) as followers OPTIONAL MATCH (u)-[:POSTED]->(p:Post) WITH u, followers, AVG(p.likes) as avg_likes WHERE followers > 100 RETURN u.id as user_id, u.name as name, followers, avg_likes, (followers + avg_likes * 10) as influence_score ORDER BY influence_score DESC LIMIT $limit """, {"limit": limit}) return influencers </code></pre></div> <h4 id="e-commerce-transaction-processing" class="position-relative d-flex align-items-center group"> E-Commerce Transaction Processing <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="e-commerce-transaction-processing" aria-haspopup="dialog" aria-label="Share link: E-Commerce Transaction Processing"> Share link </button> </h4>Complete order processing example: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-python" data-lang="python">class OrderProcessor: def __init__(self, client): self.client = client async def process_order(self, customer_id, items): """Process order with inventory check""" async with self.client.connection() as conn: # Isolation is configured server-side await conn.begin() try: # Create order order_result, _ = await conn.query( """ MATCH (c:Customer {id: $customer_id}) CREATE (o:Order { id: randomUUID(), status: 'pending', created_at: datetime(), subtotal: 0.0, tax: 0.0, total: 0.0 }) CREATE (c)-[:PLACED]->(o) RETURN o.id as order_id """, {"customer_id": customer_id}, ) order_id = order_result.rows[0]["order_id"].as_string subtotal = 0.0 # Process each item for item in items: # Check and reserve inventory inventory, _ = await conn.query( """ MATCH (p:Product {id: $product_id}) WHERE p.stock >= $quantity SET p.stock = p.stock - $quantity RETURN p.id AS id, p.name AS name, p.price AS price """, { "product_id": item["product_id"], "quantity": item["quantity"], }, ) if not inventory.rows: raise InsufficientInventoryError( f"Product {item['product_id']} out of stock" ) product = inventory.rows[0] unit_price = float(product["price"].as_decimal) line_total = unit_price * item["quantity"] subtotal += line_total # Create order line item await conn.execute( """ MATCH (o:Order {id: $order_id}), (p:Product {id: $product_id}) CREATE (li:LineItem { quantity: $quantity, unit_price: $unit_price, total: $total }) CREATE (o)-[:CONTAINS]->(li) CREATE (li)-[:FOR_PRODUCT]->(p) """, { "order_id": order_id, "product_id": item["product_id"], "quantity": item["quantity"], "unit_price": unit_price, "total": line_total, }, ) # Calculate totals tax = subtotal * 0.08 # 8% tax total = subtotal + tax # Update order totals await conn.execute( """ MATCH (o:Order {id: $order_id}) SET o.subtotal = $subtotal, o.tax = $tax, o.total = $total, o.status = 'confirmed' """, { "order_id": order_id, "subtotal": subtotal, "tax": tax, "total": total, }, ) await conn.commit() return {"order_id": order_id, "total": total} except Exception: await conn.rollback() raise </code></pre></div>Browse the tagged content below to discover comprehensive code examples and integration patterns for Geode 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