// 1. have import files car.csv and persons.csv in the ../import directory and
//
// in neo4j.conf set and then restart Neo4j
// dbms.security.allow_csv_import_from_file_urls=true


// 2. Load CSV files and create nodes

// Load persons data and create Person nodes

LOAD CSV WITH HEADERS FROM "file:///persons.csv" AS row
MERGE (p:Person {id: toInteger(row.ID)})
SET p.name = row.NAME, 
    p.address = row.ADDRESS;

// Load cars data and create Car nodes

LOAD CSV WITH HEADERS FROM 'file:///cars.csv' AS row
MERGE (c:Car {id: toInteger(row.ID)}) // Ensure unique Car nodes by ID
SET c.type = row.TYPE, 
    c.model = row.MODEL, 
    c.owner = toInteger(row.OWNER_ID); // Use OWNER_ID temporarily


// 3. Create relationships between nodes
// Match each car with its owner using the OWNER_ID property

MATCH (c:Car), (p:Person)
WHERE c.owner = p.id
MERGE (c)-[:OWNER]->(p);


// 4. Remove foreign key (OWNER_ID) from Car nodes
// The owner property is no longer needed as we have established relationships 

MATCH (c:Car)
REMOVE c.owner;