M.I.M.I.R - Multi-agent Intelligent Memory & Insight Repository

# Your First Queries **Learn basic Cypher queries to create, read, update, and delete graph data.** ## 📋 Prerequisites - NornicDB installed and running (see [Installation](installation.md)) - Connected to database (HTTP or Bolt) ## 🎯 What You'll Learn 1. Creating nodes and relationships 2. Querying graph data 3. Updating properties 4. Deleting data 5. Basic graph patterns ## 1️⃣ Creating Your First Node Let's create a person node: ```cypher CREATE (alice:Person { name: "Alice Johnson", age: 30, email: "alice@example.com" }) RETURN alice ``` **What this does:** - `CREATE` - Creates a new node - `(alice:Person ...)` - Variable name `alice`, label `Person` - `{name: ..., age: ...}` - Properties - `RETURN alice` - Returns the created node ## 2️⃣ Creating Multiple Nodes ```cypher CREATE (bob:Person {name: "Bob Smith", age: 35}), (carol:Person {name: "Carol White", age: 28}), (company:Company {name: "TechCorp", founded: 2010}) RETURN bob, carol, company ``` ## 3️⃣ Creating Relationships Connect Alice to the company: ```cypher MATCH (alice:Person {name: "Alice Johnson"}), (company:Company {name: "TechCorp"}) CREATE (alice)-[r:WORKS_AT {since: 2020, role: "Engineer"}]->(company) RETURN alice, r, company ``` **Relationship syntax:** - `(alice)-[r:WORKS_AT {...}]->(company)` - Directed relationship - `r:WORKS_AT` - Relationship type - `{since: 2020, role: "Engineer"}` - Relationship properties ## 4️⃣ Querying Data ### Find all people ```cypher MATCH (p:Person) RETURN p.name, p.age ORDER BY p.age DESC ``` ### Find relationships ```cypher MATCH (p:Person)-[r:WORKS_AT]->(c:Company) RETURN p.name, r.role, c.name ``` ### Filter with WHERE ```cypher MATCH (p:Person) WHERE p.age > 30 RETURN p.name, p.age ``` ### Pattern matching ```cypher // Find people who work at the same company MATCH (p1:Person)-[:WORKS_AT]->(c:Company)<-[:WORKS_AT]-(p2:Person) WHERE p1.name < p2.name // Avoid duplicates RETURN p1.name, p2.name, c.name ``` ## 5️⃣ Updating Data ### Update properties ```cypher MATCH (alice:Person {name: "Alice Johnson"}) SET alice.age = 31, alice.city = "San Francisco" RETURN alice ``` ### Add labels ```cypher MATCH (alice:Person {name: "Alice Johnson"}) SET alice:Employee:Manager RETURN labels(alice) ``` ### Remove properties ```cypher MATCH (alice:Person {name: "Alice Johnson"}) REMOVE alice.email RETURN alice ``` ## 6️⃣ Deleting Data ### Delete a node (must delete relationships first) ```cypher MATCH (bob:Person {name: "Bob Smith"}) DETACH DELETE bob ``` **Note:** `DETACH DELETE` removes the node and all its relationships. ### Delete specific relationships ```cypher MATCH (alice:Person)-[r:WORKS_AT]->() DELETE r ``` ### Delete all data (⚠️ Use with caution!) ```cypher MATCH (n) DETACH DELETE n ``` ## 7️⃣ Common Patterns ### Create if not exists (MERGE) ```cypher MERGE (alice:Person {name: "Alice Johnson"}) ON CREATE SET alice.created = timestamp() ON MATCH SET alice.accessed = timestamp() RETURN alice ``` ### Count nodes ```cypher MATCH (p:Person) RETURN count(p) as totalPeople ``` ### Aggregate data ```cypher MATCH (p:Person) RETURN count(p) as total, avg(p.age) as averageAge, min(p.age) as youngest, max(p.age) as oldest ``` ### Collect into list ```cypher MATCH (p:Person) RETURN collect(p.name) as allNames ``` ## 8️⃣ Practical Example: Social Network Let's build a small social network: ```cypher // Create people CREATE (alice:Person {name: "Alice", age: 30}), (bob:Person {name: "Bob", age: 35}), (carol:Person {name: "Carol", age: 28}), (dave:Person {name: "Dave", age: 32}) // Create friendships CREATE (alice)-[:FRIENDS_WITH {since: 2020}]->(bob), (alice)-[:FRIENDS_WITH {since: 2019}]->(carol), (bob)-[:FRIENDS_WITH {since: 2021}]->(dave), (carol)-[:FRIENDS_WITH {since: 2020}]->(dave) RETURN * ``` ### Find friends of friends ```cypher MATCH (alice:Person {name: "Alice"})-[:FRIENDS_WITH*2]-(fof:Person) WHERE alice <> fof RETURN DISTINCT fof.name as friendOfFriend ``` ### Find shortest path ```cypher MATCH path = shortestPath( (alice:Person {name: "Alice"})-[:FRIENDS_WITH*]-(dave:Person {name: "Dave"}) ) RETURN path ``` ## 9️⃣ Working with Properties ### JSON-like properties ```cypher CREATE (doc:Document { title: "README", metadata: { author: "Alice", version: "1.0", tags: ["documentation", "guide"] } }) RETURN doc ``` ### List properties ```cypher CREATE (person:Person { name: "Alice", skills: ["Python", "Go", "JavaScript"], languages: ["English", "Spanish"] }) RETURN person ``` ### Access nested properties ```cypher MATCH (doc:Document) RETURN doc.metadata.author, doc.metadata.tags ``` ## 🔟 Tips & Best Practices ### 1. Use parameters for dynamic values ```cypher // Instead of: MATCH (p:Person {name: "Alice"}) // Use parameters: MATCH (p:Person {name: $name}) ``` ### 2. Create indexes for better performance ```cypher CREATE INDEX person_name FOR (p:Person) ON (p.name) ``` ### 3. Use EXPLAIN to understand query plans ```cypher EXPLAIN MATCH (p:Person) WHERE p.age > 30 RETURN p ``` ### 4. Use PROFILE for performance analysis ```cypher PROFILE MATCH (p:Person)-[:WORKS_AT]->(c:Company) RETURN p, c ``` ### 5. Limit results for large datasets ```cypher MATCH (p:Person) RETURN p LIMIT 10 ``` ## 📚 Common Functions ### String functions ```cypher MATCH (p:Person) RETURN toLower(p.name) as lowercase, toUpper(p.name) as uppercase, substring(p.name, 0, 3) as first3chars ``` ### Math functions ```cypher RETURN abs(-5) as absolute, round(3.14159, 2) as rounded, sqrt(16) as squareRoot ``` ### List functions ```cypher RETURN size([1,2,3,4,5]) as listSize, head([1,2,3]) as firstElement, tail([1,2,3]) as restOfList ``` ## ⏭️ Next Steps Now that you know the basics: 1. **[Vector Search Guide](../user-guides/vector-search.md)** - Semantic search 2. **[Complete Examples](../user-guides/complete-examples.md)** - Full applications 3. **[Cypher Functions Reference](../api-reference/cypher-functions/)** - All functions 4. **[Advanced Topics](../advanced/)** - K-Means clustering, embeddings, custom functions ## 🆘 Common Issues ### "Node not found" - Make sure you created the node first - Check spelling of labels and properties ### "Cannot delete node with relationships" - Use `DETACH DELETE` instead of `DELETE` ### "Query too slow" - Create indexes on frequently queried properties - Use `EXPLAIN` to analyze query plan - Limit result sets with `LIMIT` --- **Need more examples?** → **[Complete Examples](../user-guides/complete-examples.md)** **Ready for advanced features?** → **[User Guides](../user-guides/)**