GQL Tutorial | Geode Database

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This guide will take you from GQL basics to writing advanced graph queries through hands-on examples and exercises. <h3 id="what-youll-learn" class="position-relative d-flex align-items-center group"> What You&rsquo;ll Learn <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="what-youll-learn" aria-haspopup="dialog" aria-label="Share link: What Youll Learn"> Share link </button> </h3>By the end of this tutorial, you will be able to: <ul> <li>Create and query nodes and relationships</li> <li>Use pattern matching to find graph structures</li> <li>Filter, sort, and paginate results</li> <li>Aggregate data with COUNT, SUM, AVG, and more</li> <li>Modify graph data with CREATE, SET, and DELETE</li> <li>Write complex queries with multiple clauses</li> <li>Optimize queries for performance</li> </ul> <h3 id="prerequisites" class="position-relative d-flex align-items-center group"> Prerequisites <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="prerequisites" aria-haspopup="dialog" aria-label="Share link: Prerequisites"> Share link </button> </h3>Before starting: <ol> <li>Geode installed and running - See <a href="/docs/overview/" >Installation Guide</a> </li> <li>Access to the Geode shell - <code>geode shell</code></li> <li>No prior GQL experience required - SQL knowledge helpful but not necessary</li> </ol> <h3 id="part-1-getting-started" class="position-relative d-flex align-items-center group"> Part 1: Getting Started <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="part-1-getting-started" aria-haspopup="dialog" aria-label="Share link: Part 1: Getting Started"> Share link </button> </h3> <h4 id="connecting-to-geode" class="position-relative d-flex align-items-center group"> Connecting to Geode <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="connecting-to-geode" aria-haspopup="dialog" aria-label="Share link: Connecting to Geode"> Share link </button> </h4>Start the Geode interactive shell: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-bash" data-lang="bash">geode shell # Output: # Geode Shell v0.2.18 # Connected to localhost:3141 # Type \help for commands # geode> </code></pre></div> <h4 id="creating-a-sample-graph" class="position-relative d-flex align-items-center group"> Creating a Sample Graph <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-a-sample-graph" aria-haspopup="dialog" aria-label="Share link: Creating a Sample Graph"> Share link </button> </h4>Let’s create a simple social network: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Create the graph CREATE GRAPH SocialNetwork; USE SocialNetwork; -- Create some people CREATE (:Person {name: 'Alice', age: 30, city: 'Seattle'}); CREATE (:Person {name: 'Bob', age: 28, city: 'Portland'}); CREATE (:Person {name: 'Carol', age: 35, city: 'Seattle'}); CREATE (:Person {name: 'David', age: 32, city: 'Vancouver'}); CREATE (:Person {name: 'Eve', age: 27, city: 'Portland'}); </code></pre></div>What happened? <ul> <li><code>CREATE GRAPH</code> creates a new graph database</li> <li><code>USE</code> switches to that graph</li> <li><code>CREATE</code> with <code>(:Person {...})</code> creates nodes with the <code>Person</code> label and properties</li> </ul> <h4 id="creating-relationships" class="position-relative d-flex align-items-center group"> Creating 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="creating-relationships" aria-haspopup="dialog" aria-label="Share link: Creating Relationships"> Share link </button> </h4>Connect the people with KNOWS relationships: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Create friendships MATCH (a:Person {name: 'Alice'}), (b:Person {name: 'Bob'}) CREATE (a)-[:KNOWS {since: 2020}]->(b); MATCH (a:Person {name: 'Alice'}), (c:Person {name: 'Carol'}) CREATE (a)-[:KNOWS {since: 2018}]->(c); MATCH (b:Person {name: 'Bob'}), (c:Person {name: 'Carol'}) CREATE (b)-[:KNOWS {since: 2021}]->(c); MATCH (c:Person {name: 'Carol'}), (d:Person {name: 'David'}) CREATE (c)-[:KNOWS {since: 2019}]->(d); MATCH (d:Person {name: 'David'}), (e:Person {name: 'Eve'}) CREATE (d)-[:KNOWS {since: 2022}]->(e); </code></pre></div>Graph Structure Created: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-fallback" data-lang="fallback">Alice --KNOWS--> Bob --KNOWS--> Carol --KNOWS--> David --KNOWS--> Eve | ^ +----------KNOWS---------------+ </code></pre></div> <h3 id="part-2-basic-queries" class="position-relative d-flex align-items-center group"> Part 2: Basic 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="part-2-basic-queries" aria-haspopup="dialog" aria-label="Share link: Part 2: Basic Queries"> Share link </button> </h3> <h4 id="query-1-find-all-people" class="position-relative d-flex align-items-center group"> Query 1: Find All People <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-1-find-all-people" aria-haspopup="dialog" aria-label="Share link: Query 1: Find All People"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">MATCH (p:Person) RETURN p.name, p.age, p.city; </code></pre></div>Expected Output: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-fallback" data-lang="fallback">| p.name | p.age | p.city | |---------|-------|-----------| | Alice | 30 | Seattle | | Bob | 28 | Portland | | Carol | 35 | Seattle | | David | 32 | Vancouver | | Eve | 27 | Portland | </code></pre></div>Explanation: <ul> <li><code>MATCH (p:Person)</code> finds all nodes with the <code>Person</code> label</li> <li><code>p</code> is a variable that refers to each matched node</li> <li><code>RETURN p.name, p.age, p.city</code> selects which properties to display</li> </ul> <h4 id="query-2-filter-with-where" class="position-relative d-flex align-items-center group"> Query 2: Filter 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="query-2-filter-with-where" aria-haspopup="dialog" aria-label="Share link: Query 2: Filter with WHERE"> Share link </button> </h4>Find people over 30: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">MATCH (p:Person) WHERE p.age > 30 RETURN p.name, p.age; </code></pre></div>Output: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-fallback" data-lang="fallback">| p.name | p.age | |--------|-------| | Carol | 35 | | David | 32 | </code></pre></div> <h4 id="query-3-multiple-conditions" class="position-relative d-flex align-items-center group"> Query 3: Multiple Conditions <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-3-multiple-conditions" aria-haspopup="dialog" aria-label="Share link: Query 3: Multiple Conditions"> Share link </button> </h4>Find people in Seattle under 35: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">MATCH (p:Person) WHERE p.city = 'Seattle' AND p.age < 35 RETURN p.name, p.age, p.city; </code></pre></div>Output: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-fallback" data-lang="fallback">| p.name | p.age | p.city | |--------|-------|---------| | Alice | 30 | Seattle | </code></pre></div> <h4 id="query-4-sorting-results" class="position-relative d-flex align-items-center group"> Query 4: Sorting 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="query-4-sorting-results" aria-haspopup="dialog" aria-label="Share link: Query 4: Sorting Results"> Share link </button> </h4>Order by age (descending): <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">MATCH (p:Person) RETURN p.name, p.age ORDER BY p.age DESC; </code></pre></div>Output: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-fallback" data-lang="fallback">| p.name | p.age | |--------|-------| | Carol | 35 | | David | 32 | | Alice | 30 | | Bob | 28 | | Eve | 27 | </code></pre></div> <h4 id="query-5-limiting-results" class="position-relative d-flex align-items-center group"> Query 5: 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="query-5-limiting-results" aria-haspopup="dialog" aria-label="Share link: Query 5: Limiting Results"> Share link </button> </h4>Get the 3 oldest people: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">MATCH (p:Person) RETURN p.name, p.age ORDER BY p.age DESC LIMIT 3; </code></pre></div>Output: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-fallback" data-lang="fallback">| p.name | p.age | |--------|-------| | Carol | 35 | | David | 32 | | Alice | 30 | </code></pre></div> <h3 id="part-3-relationship-queries" class="position-relative d-flex align-items-center group"> Part 3: Relationship 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="part-3-relationship-queries" aria-haspopup="dialog" aria-label="Share link: Part 3: Relationship Queries"> Share link </button> </h3> <h4 id="query-6-find-direct-connections" class="position-relative d-flex align-items-center group"> Query 6: Find Direct Connections <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-6-find-direct-connections" aria-haspopup="dialog" aria-label="Share link: Query 6: Find Direct Connections"> Share link </button> </h4>Find who Alice knows: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">MATCH (alice:Person {name: 'Alice'})-[:KNOWS]->(friend:Person) RETURN friend.name; </code></pre></div>Output: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-fallback" data-lang="fallback">| friend.name | |-------------| | Bob | | Carol | </code></pre></div>Explanation: <ul> <li><code>(alice:Person {name: 'Alice'})</code> matches the specific Alice node</li> <li><code>-[:KNOWS]-></code> matches outgoing KNOWS relationships</li> <li><code>(friend:Person)</code> captures the connected Person nodes</li> </ul> <h4 id="query-7-bidirectional-relationships" class="position-relative d-flex align-items-center group"> Query 7: Bidirectional 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="query-7-bidirectional-relationships" aria-haspopup="dialog" aria-label="Share link: Query 7: Bidirectional Relationships"> Share link </button> </h4>Find anyone connected to Bob (in or out): <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">MATCH (bob:Person {name: 'Bob'})-[:KNOWS]-(connected:Person) RETURN connected.name; </code></pre></div>Output: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-fallback" data-lang="fallback">| connected.name | |----------------| | Alice | | Carol | </code></pre></div>Note: <code>-[:KNOWS]-</code> (no arrow) matches both directions. <h4 id="query-8-relationship-properties" class="position-relative d-flex align-items-center group"> Query 8: 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="query-8-relationship-properties" aria-haspopup="dialog" aria-label="Share link: Query 8: Relationship Properties"> Share link </button> </h4>Find when friendships were created: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">MATCH (a:Person)-[k:KNOWS]->(b:Person) RETURN a.name, b.name, k.since; </code></pre></div>Output: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-fallback" data-lang="fallback">| a.name | b.name | k.since | |--------|--------|---------| | Alice | Bob | 2020 | | Alice | Carol | 2018 | | Bob | Carol | 2021 | | Carol | David | 2019 | | David | Eve | 2022 | </code></pre></div> <h4 id="query-9-friends-of-friends" class="position-relative d-flex align-items-center group"> Query 9: Friends of Friends <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-9-friends-of-friends" aria-haspopup="dialog" aria-label="Share link: Query 9: Friends of Friends"> Share link </button> </h4>Find Alice’s friends-of-friends: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">MATCH (alice:Person {name: 'Alice'})-[:KNOWS*2]->(fof:Person) WHERE fof <> alice RETURN DISTINCT fof.name; </code></pre></div>Output: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-fallback" data-lang="fallback">| fof.name | |----------| | Carol | | David | </code></pre></div>Explanation: <ul> <li><code>-[:KNOWS*2]-></code> means exactly 2 hops</li> <li><code>WHERE fof <> alice</code> excludes Alice herself</li> <li><code>DISTINCT</code> removes duplicates</li> </ul> <h4 id="query-10-variable-length-paths" class="position-relative d-flex align-items-center group"> Query 10: 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="query-10-variable-length-paths" aria-haspopup="dialog" aria-label="Share link: Query 10: Variable-Length Paths"> Share link </button> </h4>Find everyone reachable from Alice: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">MATCH (alice:Person {name: 'Alice'})-[:KNOWS*1..4]->(reachable:Person) RETURN DISTINCT reachable.name; </code></pre></div>Output: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-fallback" data-lang="fallback">| reachable.name | |----------------| | Bob | | Carol | | David | | Eve | </code></pre></div>Explanation: <code>-[:KNOWS*1..4]-></code> matches paths of 1 to 4 hops. <h3 id="part-4-aggregation" class="position-relative d-flex align-items-center group"> Part 4: Aggregation <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="part-4-aggregation" aria-haspopup="dialog" aria-label="Share link: Part 4: Aggregation"> Share link </button> </h3> <h4 id="query-11-count-nodes" class="position-relative d-flex align-items-center group"> Query 11: Count Nodes <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-11-count-nodes" aria-haspopup="dialog" aria-label="Share link: Query 11: Count Nodes"> Share link </button> </h4>Count all people: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">MATCH (p:Person) RETURN count(p) AS total_people; </code></pre></div>Output: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-fallback" data-lang="fallback">| total_people | |--------------| | 5 | </code></pre></div> <h4 id="query-12-group-by-and-count" class="position-relative d-flex align-items-center group"> Query 12: Group By and Count <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-12-group-by-and-count" aria-haspopup="dialog" aria-label="Share link: Query 12: Group By and Count"> Share link </button> </h4>Count people by city: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">MATCH (p:Person) RETURN p.city, count(p) AS population ORDER BY population DESC; </code></pre></div>Output: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-fallback" data-lang="fallback">| p.city | population | |-----------|------------| | Seattle | 2 | | Portland | 2 | | Vancouver | 1 | </code></pre></div> <h4 id="query-13-multiple-aggregations" class="position-relative d-flex align-items-center group"> Query 13: Multiple Aggregations <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-13-multiple-aggregations" aria-haspopup="dialog" aria-label="Share link: Query 13: Multiple Aggregations"> Share link </button> </h4>Calculate age statistics by city: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">MATCH (p:Person) RETURN p.city, count(p) AS count, avg(p.age) AS avg_age, min(p.age) AS youngest, max(p.age) AS oldest; </code></pre></div>Output: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-fallback" data-lang="fallback">| p.city | count | avg_age | youngest | oldest | |-----------|-------|---------|----------|--------| | Seattle | 2 | 32.5 | 30 | 35 | | Portland | 2 | 27.5 | 27 | 28 | | Vancouver | 1 | 32.0 | 32 | 32 | </code></pre></div> <h4 id="query-14-count-relationships" class="position-relative d-flex align-items-center group"> Query 14: Count 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="query-14-count-relationships" aria-haspopup="dialog" aria-label="Share link: Query 14: Count Relationships"> Share link </button> </h4>Count friendships per person: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">MATCH (p:Person)-[:KNOWS]->(friend) RETURN p.name, count(friend) AS friends ORDER BY friends DESC; </code></pre></div>Output: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-fallback" data-lang="fallback">| p.name | friends | |--------|---------| | Alice | 2 | | Bob | 1 | | Carol | 1 | | David | 1 | </code></pre></div> <h4 id="query-15-collect-aggregation" class="position-relative d-flex align-items-center group"> Query 15: COLLECT Aggregation <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-15-collect-aggregation" aria-haspopup="dialog" aria-label="Share link: Query 15: COLLECT Aggregation"> Share link </button> </h4>Collect friends into a list: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">MATCH (p:Person)-[:KNOWS]->(friend) RETURN p.name, collect(friend.name) AS friend_list; </code></pre></div>Output: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-fallback" data-lang="fallback">| p.name | friend_list | |--------|------------------| | Alice | [Bob, Carol] | | Bob | [Carol] | | Carol | [David] | | David | [Eve] | </code></pre></div> <h3 id="part-5-data-modification" class="position-relative d-flex align-items-center group"> Part 5: Data Modification <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="part-5-data-modification" aria-haspopup="dialog" aria-label="Share link: Part 5: Data Modification"> Share link </button> </h3> <h4 id="query-16-update-properties" class="position-relative d-flex align-items-center group"> Query 16: Update 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="query-16-update-properties" aria-haspopup="dialog" aria-label="Share link: Query 16: Update Properties"> Share link </button> </h4>Update Alice’s age: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">MATCH (p:Person {name: 'Alice'}) SET p.age = 31 RETURN p.name, p.age; </code></pre></div> <h4 id="query-17-add-new-properties" class="position-relative d-flex align-items-center group"> Query 17: Add New 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="query-17-add-new-properties" aria-haspopup="dialog" aria-label="Share link: Query 17: Add New Properties"> Share link </button> </h4>Add email to all people: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">MATCH (p:Person) SET p.email = toLower(p.name) + '@example.com' RETURN p.name, p.email; </code></pre></div> <h4 id="query-18-remove-properties" class="position-relative d-flex align-items-center group"> Query 18: Remove 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="query-18-remove-properties" aria-haspopup="dialog" aria-label="Share link: Query 18: Remove Properties"> Share link </button> </h4>Remove the email property: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">MATCH (p:Person) REMOVE p.email RETURN p.name, p.email; </code></pre></div> <h4 id="query-19-delete-relationships" class="position-relative d-flex align-items-center group"> Query 19: Delete 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="query-19-delete-relationships" aria-haspopup="dialog" aria-label="Share link: Query 19: Delete Relationships"> Share link </button> </h4>Remove friendship between Alice and Bob: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">MATCH (a:Person {name: 'Alice'})-[k:KNOWS]->(b:Person {name: 'Bob'}) DELETE k; </code></pre></div> <h4 id="query-20-delete-nodes" class="position-relative d-flex align-items-center group"> Query 20: Delete Nodes <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-20-delete-nodes" aria-haspopup="dialog" aria-label="Share link: Query 20: Delete Nodes"> Share link </button> </h4>Delete a person (must delete relationships first): <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- First, delete relationships MATCH (p:Person {name: 'Eve'})-[r]-() DELETE r; -- Then delete the node MATCH (p:Person {name: 'Eve'}) DELETE p; -- Or use DETACH DELETE to do both MATCH (p:Person {name: 'Eve'}) DETACH DELETE p; </code></pre></div> <h3 id="part-6-advanced-queries" class="position-relative d-flex align-items-center group"> Part 6: Advanced 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="part-6-advanced-queries" aria-haspopup="dialog" aria-label="Share link: Part 6: Advanced Queries"> Share link </button> </h3> <h4 id="query-21-with-clause" class="position-relative d-flex align-items-center group"> Query 21: WITH Clause <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-21-with-clause" aria-haspopup="dialog" aria-label="Share link: Query 21: WITH Clause"> Share link </button> </h4>Use WITH for query pipelines: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">MATCH (p:Person)-[:KNOWS]->(friend) WITH p, count(friend) AS friend_count WHERE friend_count >= 2 RETURN p.name, friend_count; </code></pre></div>Explanation: WITH passes intermediate results to subsequent clauses. <h4 id="query-22-optional-match" class="position-relative d-flex align-items-center group"> Query 22: OPTIONAL 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="query-22-optional-match" aria-haspopup="dialog" aria-label="Share link: Query 22: OPTIONAL MATCH"> Share link </button> </h4>Find people and their friends (including those with no friends): <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">MATCH (p:Person) OPTIONAL MATCH (p)-[:KNOWS]->(friend) RETURN p.name, count(friend) AS friends; </code></pre></div>Note: OPTIONAL MATCH is like a LEFT JOIN - it returns rows even when no match is found. <h4 id="query-23-case-expressions" class="position-relative d-flex align-items-center group"> Query 23: 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="query-23-case-expressions" aria-haspopup="dialog" aria-label="Share link: Query 23: CASE Expressions"> Share link </button> </h4>Categorize people by age: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">MATCH (p:Person) RETURN p.name, p.age, CASE WHEN p.age < 30 THEN 'Young' WHEN p.age < 35 THEN 'Middle' ELSE 'Senior' END AS category; </code></pre></div> <h4 id="query-24-coalesce-for-defaults" class="position-relative d-flex align-items-center group"> Query 24: COALESCE for Defaults <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-24-coalesce-for-defaults" aria-haspopup="dialog" aria-label="Share link: Query 24: COALESCE for Defaults"> Share link </button> </h4>Handle missing properties: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">MATCH (p:Person) RETURN p.name, coalesce(p.nickname, p.name) AS display_name; </code></pre></div> <h4 id="query-25-shortest-path" class="position-relative d-flex align-items-center group"> Query 25: 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="query-25-shortest-path" aria-haspopup="dialog" aria-label="Share link: Query 25: Shortest Path"> Share link </button> </h4>Find shortest path between two people: <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">MATCH path = shortestPath( (alice:Person {name: 'Alice'})-[*]-(eve:Person {name: 'Eve'}) ) RETURN [n IN nodes(path) | n.name] AS path_names, length(path) AS distance; </code></pre></div> <h3 id="practice-exercises" class="position-relative d-flex align-items-center group"> Practice Exercises <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="practice-exercises" aria-haspopup="dialog" aria-label="Share link: Practice Exercises"> Share link </button> </h3> <h4 id="exercise-1-basic-query" class="position-relative d-flex align-items-center group"> Exercise 1: Basic 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="exercise-1-basic-query" aria-haspopup="dialog" aria-label="Share link: Exercise 1: Basic Query"> Share link </button> </h4>Task: Find all people in Portland, sorted by age (youngest first). <details> <summary>Solution</summary> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">MATCH (p:Person) WHERE p.city = 'Portland' RETURN p.name, p.age ORDER BY p.age ASC; </code></pre></div></details> <h4 id="exercise-2-relationship-query" class="position-relative d-flex align-items-center group"> Exercise 2: Relationship 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="exercise-2-relationship-query" aria-haspopup="dialog" aria-label="Share link: Exercise 2: Relationship Query"> Share link </button> </h4>Task: Find all pairs of people who know each other and both live in the same city. <details> <summary>Solution</summary> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">MATCH (a:Person)-[:KNOWS]->(b:Person) WHERE a.city = b.city RETURN a.name, b.name, a.city; </code></pre></div></details> <h4 id="exercise-3-aggregation" class="position-relative d-flex align-items-center group"> Exercise 3: Aggregation <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="exercise-3-aggregation" aria-haspopup="dialog" aria-label="Share link: Exercise 3: Aggregation"> Share link </button> </h4>Task: Find the average age of people who have at least 1 friend. <details> <summary>Solution</summary> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">MATCH (p:Person)-[:KNOWS]->() WITH DISTINCT p RETURN avg(p.age) AS avg_age; </code></pre></div></details> <h4 id="exercise-4-path-query" class="position-relative d-flex align-items-center group"> Exercise 4: Path 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="exercise-4-path-query" aria-haspopup="dialog" aria-label="Share link: Exercise 4: Path Query"> Share link </button> </h4>Task: Find all paths of length 3 starting from Alice. <details> <summary>Solution</summary> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">MATCH path = (alice:Person {name: 'Alice'})-[:KNOWS*3]->(end) RETURN [n IN nodes(path) | n.name] AS path; </code></pre></div></details> <h4 id="exercise-5-complex-query" class="position-relative d-flex align-items-center group"> Exercise 5: Complex 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="exercise-5-complex-query" aria-haspopup="dialog" aria-label="Share link: Exercise 5: Complex Query"> Share link </button> </h4>Task: For each city, find the most connected person (person with the most outgoing KNOWS relationships). <details> <summary>Solution</summary> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">MATCH (p:Person)-[:KNOWS]->(friend) WITH p, count(friend) AS connections ORDER BY connections DESC WITH p.city AS city, collect({name: p.name, connections: connections})[0] AS top RETURN city, top.name AS most_connected, top.connections; </code></pre></div></details> <h3 id="common-mistakes" class="position-relative d-flex align-items-center group"> Common Mistakes <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-mistakes" aria-haspopup="dialog" aria-label="Share link: Common Mistakes"> Share link </button> </h3> <h4 id="mistake-1-missing-variable" class="position-relative d-flex align-items-center group"> Mistake 1: Missing 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="mistake-1-missing-variable" aria-haspopup="dialog" aria-label="Share link: Mistake 1: Missing Variable"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Wrong: No variable to reference MATCH (:Person) RETURN name; -- Error: name is not bound -- Right: Use a variable MATCH (p:Person) RETURN p.name; </code></pre></div> <h4 id="mistake-2-forgetting-distinct" class="position-relative d-flex align-items-center group"> Mistake 2: Forgetting DISTINCT <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="mistake-2-forgetting-distinct" aria-haspopup="dialog" aria-label="Share link: Mistake 2: Forgetting DISTINCT"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- May have duplicates MATCH (a)-[:KNOWS*1..3]->(b) RETURN b.name; -- Use DISTINCT to remove duplicates MATCH (a)-[:KNOWS*1..3]->(b) RETURN DISTINCT b.name; </code></pre></div> <h4 id="mistake-3-deleting-nodes-with-relationships" class="position-relative d-flex align-items-center group"> Mistake 3: Deleting Nodes with 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="mistake-3-deleting-nodes-with-relationships" aria-haspopup="dialog" aria-label="Share link: Mistake 3: Deleting Nodes with Relationships"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Wrong: Will fail if node has relationships MATCH (p:Person {name: 'Alice'}) DELETE p; -- Right: Use DETACH DELETE MATCH (p:Person {name: 'Alice'}) DETACH DELETE p; </code></pre></div> <h4 id="mistake-4-cartesian-product" class="position-relative d-flex align-items-center group"> Mistake 4: Cartesian Product <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="mistake-4-cartesian-product" aria-haspopup="dialog" aria-label="Share link: Mistake 4: Cartesian Product"> Share link </button> </h4><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Warning: This creates a cartesian product (every combination) MATCH (a:Person), (b:Person) WHERE a.city = b.city RETURN a.name, b.name; -- Better: Be explicit about the pattern MATCH (a:Person)-[:LIVES_IN]->(c:City)<-[:LIVES_IN]-(b:Person) RETURN a.name, b.name; </code></pre></div> <h3 id="next-steps" class="position-relative d-flex align-items-center group"> Next Steps <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="next-steps" aria-haspopup="dialog" aria-label="Share link: Next Steps"> Share link </button> </h3>Congratulations on completing the GQL tutorial! Continue learning with: <ul> <li><a href="/docs/gql/advanced-patterns/" >Advanced Patterns</a> - Complex query techniques</li> <li><a href="/docs/gql-reference/pattern-matching/" >Pattern Matching Reference</a> - Complete pattern syntax</li> <li><a href="/docs/gql-reference/aggregations/" >Aggregations Reference</a> - All aggregation functions</li> <li><a href="/docs/query/explain-profile/" >EXPLAIN and PROFILE</a> - Query analysis and optimization</li> <li><a href="/docs/tutorials/" >Tutorials</a> - More hands-on guides</li> <li><a href="/docs/gql/guide/" >GQL Guide</a> - Complete language reference</li> </ul> <h3 id="quick-reference-card" class="position-relative d-flex align-items-center group"> Quick Reference Card <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="quick-reference-card" aria-haspopup="dialog" aria-label="Share link: Quick Reference Card"> Share link </button> </h3><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Node pattern (variable:Label {prop: value}) -- Relationship pattern -[var:TYPE {prop: value}]-> -- Variable-length path -[:TYPE*min..max]-> -- Query structure MATCH pattern WHERE condition WITH projection RETURN expression ORDER BY column LIMIT n -- Aggregations count(*), sum(n.x), avg(n.x), min(n.x), max(n.x), collect(n.x) -- Modification CREATE (n:Label {props}) SET n.prop = value REMOVE n.prop DELETE n DETACH DELETE n </code></pre></div><hr> Last Updated: January 28, 2026 Geode Version: v0.2.18+ GQL Compliance: ISO/IEC 39075:2024