A simple neo4j based recommendations engine

recommender.md

Recommendations Engine in neo4j

Node Types

• Project: { type: "project", id: <id>, featured: <bool> }
• User: { type: "user", id: <id> }
• Tag: { type: "tag", name: <name> }

Relationships

• (project)-[:TAG]->(tag)
• (user)-[:FOLLOW]->(project|user)
• (user)-[:INTEREST]-(tag)
• (user)-[:INTERACT {action: 'view|fund|create'}]->(project)

Queries

• Featured projects in a tag

START tag=node(*)
MATCH (tag)<-[:TAG]-(cat)
WHERE tag.type = "tag"
AND tag.name = <tagname>
AND cat.featured! = true
RETURN cat;

• Recommend projects to a user based on users who view projects like him

START user=node(*)
MATCH (user)-[:INTERACT]->(iproj)<-[:INTERACT]-(user2)-[:INTERACT]->(proj)
WHERE user.type = "user"
AND user.id = <id>
RETURN proj, COUNT(proj);

• Recommend projects to a user based on categories interested in

START user=node(*)
MATCH (user)-[:INTEREST]->(cat)<-[:TAG]-(proj)
WHERE user.type = "user"
AND user.id = <id>
RETURN proj, COUNT(proj);

• Recommend categories to a user based on projects viewed

START user=node(*)
MATCH (user)-[:INTERACT]->(proj)-[:TAG]->(cat)
WHERE user.type = "user"
AND user.id = <id>
RETURN cat, COUNT(cat);