SQLite Graph Ext

Details

External ID

45751339

Source

HN

Company

—

Product

SQLite Graph Ext

Website domain

github.com

Launched

Oct. 29, 2025

Cohort

—

Upvotes

35

Upvotes percentile

0.8301886792452831

Tags

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Fetched at

Sept. 7, 2026, 9:25 p.m.

Updated at

Sept. 7, 2026, 9:25 p.m.

Description

I've been working on adding graph database capabilities to SQLite with support for the Cypher query language. As of this week, both CREATE and MATCH operations work with full relationship support.Here's what it looks like: import sqlite3 conn = sqlite3.connect(":memory:") conn.load_extension("./libgraph.so") conn.execute("CREATE VIRTUAL TABLE graph USING graph()") # Create a social network conn.execute("""SELECT cypher_execute(' CREATE (alice:Person {name: "Alice", age: 30}), (bob:Person {name: "Bob", age: 25}), (alice)-[:KNOWS {since: 2020}]->(bob) ')""") # Query the graph with relationship patterns conn.execute("""SELECT cypher_execute(' MATCH (a:Person)-[r:KNOWS]->(b:Person) WHERE a.age > 25 RETURN a, r, b ')""") The interesting part was building the complete execution pipeline - lexer, parser, logical planner, physical planner, and an iterator-based executor using the Volcano model. All in C99 with no dependencies beyond SQLite.What works now: - Full CREATE: nodes, relationships, properties, chained patterns (70/70 openCypher TCK tests) - MATCH with relationship patterns: (a)-[r:TYPE]->(b) with label and type filtering - WHERE clause: property comparisons on nodes (=, >, <, >=, <=, <>) - RETURN: basic projection with JSON serialization - Virtual table integration for mixing SQL and CypherPerformance: - 340K nodes/sec inserts (consistent to 1M nodes) - 390K edges/sec for relationships - 180K nodes/sec scans with WHERE filteringCurrent limitations (alpha): - Only forward relationships (no `<-[r]-` or bidirectional `-[r]-`) - No relationship property filtering in WHERE (e.g., `WHERE r.weight > 5`) - No variable-length paths yet (e.g., `[r*1..3]`) - No aggregations, ORDER BY, property projection in RETURN - Must use double quotes for strings: {name: "Alice"} not {name: 'Alice'}This is alpha - API may change. But core graph query patterns work! The execution pipeline handles CREATE/MATCH/WHERE/RETURN end-to-end.Next up: bidirectional relationships, property projection, aggregations. Roadmap targets full Cypher support by Q1 2026.Built as part of Agentflare AI, but it's standalone and MIT licensed. Would love feedback on what to prioritize.GitHub: https://github.com/agentflare-ai/sqlite-graphHappy to answer questions about the implementation!

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