This is what the instance model will be refactored to:
Creating Language Nodes
Execute this code to refactor the graph to turn the languages property values into Language nodes:
MATCH (m:Movie)
UNWIND m.languages AS language
WITH language, collect(m) AS movies
MERGE (l:Language {name:language})
WITH l, movies
UNWIND movies AS m
WITH l,m
MERGE (m)-[:IN_LANGUAGE]->(l);
MATCH (m:Movie)
SET m.languages = nullModifying the Cypher statement
This is the Cypher code for what our use case used to be before the refactoring.
MATCH (m:Movie)
WHERE 'Italian' IN m.languages
RETURN m.titleThis query can now be modified to instead use the newly-created Language node.
MATCH (m:Movie)-[:IN_LANGUAGE]-(l:Language)
WHERE l.name = 'Italian'
RETURN m.titleThis is the only use case that deals with languages so we need not retest all of our queries after the refactor.
Validate Results
Once you have run the query, click the Check Database button and we will check the database for you.
Hint
You will need to run the Cypher statement in Creating Language Nodes to perform this refactoring.
Then click Try Again.
Solution
To pass the challenge, run the following queries in sequence by clicking the Run in Sandbox.
MATCH (n) DETACH DELETE n;
MERGE (apollo:Movie {title: 'Apollo 13', tmdbId: 568, released: '1995-06-30', imdbRating: 7.6, genres: ['Drama', 'Adventure', 'IMAX']})
MERGE (tom:Person {name: 'Tom Hanks', tmdbId: 31, born: '1956-07-09'})
MERGE (meg:Person {name: 'Meg Ryan', tmdbId: 5344, born: '1961-11-19'})
MERGE (danny:Person {name: 'Danny DeVito', tmdbId: 518, born: '1944-11-17'})
MERGE (sleep:Movie {title: 'Sleepless in Seattle', tmdbId: 858, released: '1993-06-25', imdbRating: 6.8, genres: ['Comedy', 'Drama', 'Romance']})
MERGE (hoffa:Movie {title: 'Hoffa', tmdbId: 10410, released: '1992-12-25', imdbRating: 6.6, genres: ['Crime', 'Drama']})
MERGE (jack:Person {name: 'Jack Nicholson', tmdbId: 514, born: '1937-04-22'})
MERGE (sandy:User {name: 'Sandy Jones', userId: 534})
MERGE (clinton:User {name: 'Clinton Spencer', userId: 105})
MERGE (tom)-[:ACTED_IN {role: 'Jim Lovell'}]->(apollo)
MERGE (tom)-[:ACTED_IN {role: 'Sam Baldwin'}]->(sleep)
MERGE (meg)-[:ACTED_IN {role: 'Annie Reed'}]->(sleep)
MERGE (danny)-[:ACTED_IN {role: 'Bobby Ciaro'}]->(hoffa)
MERGE (danny)-[:DIRECTED]->(hoffa)
MERGE (jack)-[:ACTED_IN {role: 'Jimmy Hoffa'}]->(hoffa)
MERGE (sandy)-[:RATED {rating:5}]->(apollo)
MERGE (sandy)-[:RATED {rating:4}]->(sleep)
MERGE (clinton)-[:RATED {rating:3}]->(apollo)
MERGE (clinton)-[:RATED {rating:3}]->(sleep)
MERGE (clinton )-[:RATED {rating:3}]->(hoffa)
MERGE (casino:Movie {title: 'Casino', tmdbId: 524, released: '1995-11-22', imdbRating: 8.2, genres: ['Drama','Crime']})
MERGE (martin:Person {name: 'Martin Scorsese', tmdbId: 1032})
MERGE (martin)-[:DIRECTED]->(casino)
SET tom:Actor
SET meg:Actor
SET danny:Actor
SET jack:Actor
SET danny:Director
SET martin:Director
SET apollo.languages = ['English']
SET sleep.languages = ['English']
SET hoffa.languages = ['English', 'Italian', 'Latin']
SET casino.languages = ['English'];MATCH (m:Movie)
UNWIND m.languages AS language
WITH language, collect(m) AS movies
MERGE (l:Language {name:language})
WITH l, movies
UNWIND movies AS m
WITH l,m
MERGE (m)-[:IN_LANGUAGE]->(l);
MATCH (m:Movie)
SET m.languages = nullThen click Try Again.
Summary
In this challenge, you demonstrated that you can refactor the graph to add nodes to replace duplication in properties.
In the next challenge, you will perform some additional factoring to eliminate duplication.