سیستم توصیه‌کننده با آپاچی AGE

-- Creating the graph.
SELECT create_graph('RecommenderSystem');


-- Adding user.
SELECT * FROM cypher('RecommenderSystem', $$
    CREATE (:Person {name: 'Abigail'})
$$) AS (a agtype);


-- Adding movies.
SELECT * FROM cypher('RecommenderSystem', $$
    CREATE (:Movie {title: 'The Matrix'}),
           (:Movie {title: 'Shrek'}),
           (:Movie {title: 'The Blair Witch Project'}),
           (:Movie {title: 'Jurassic Park'}),
           (:Movie {title: 'Thor: Love and Thunder'})
$$) AS (a agtype);


-- Adding categories.
SELECT * FROM cypher('RecommenderSystem', $$
    CREATE (:Category {name: 'Action'}),
           (:Category {name: 'Comedy'}),
           (:Category {name: 'Horror'})
$$) AS (a agtype);

-- User preferences.
SELECT * FROM cypher('RecommenderSystem', $$
    MATCH (a:Person {name: 'Abigail'}), (A:Category), (C:Category), (H:Category)
    WHERE A.name = 'Action' AND C.name = 'Comedy' AND H.name = 'Horror' 
    CREATE (a)-[:RATING {rating: 3}]->(C),
           (a)-[:RATING {rating: 1}]->(A),
           (a)-[:RATING {rating: 0}]->(H)
$$) AS (a agtype);

-- The Matrix and it's relationship with Categories.
SELECT * FROM cypher('RecommenderSystem', $$
    MATCH (matrix:Movie {title: 'The Matrix'}), (A:Category), (C:Category), (H:Category)
    WHERE A.name = 'Action' AND C.name = 'Comedy' AND H.name = 'Horror' 
    CREATE (matrix)-[:RATING {rating: 0}]->(C),
           (matrix)-[:RATING {rating: 4}]->(A),
           (matrix)-[:RATING {rating: 0}]->(H)
$$) AS (a agtype);

-- Shrek and it's relationship with Categories.
SELECT * FROM cypher('RecommenderSystem', $$
    MATCH (shrek:Movie {title: 'Shrek'}), (A:Category), (C:Category), (H:Category)
    WHERE A.name = 'Action' AND C.name = 'Comedy' AND H.name = 'Horror' 
    CREATE (shrek)-[:RATING {rating: 4}]->(C),
           (shrek)-[:RATING {rating: 2}]->(A),
           (shrek)-[:RATING {rating: 0}]->(H)
$$) AS (a agtype);

-- The Blair Witch Project and it's relationship with Categories.
SELECT * FROM cypher('RecommenderSystem', $$
    MATCH (witch:Movie {title: 'The Blair Witch Project'}), (A:Category), (C:Category), (H:Category)
    WHERE A.name = 'Action' AND C.name = 'Comedy' AND H.name = 'Horror' 
    CREATE (witch)-[:RATING {rating: 0}]->(C),
           (witch)-[:RATING {rating: 0}]->(A),
           (witch)-[:RATING {rating: 4}]->(H)
$$) AS (a agtype);

-- Jurassic Park and it's relationship with Categories.
SELECT * FROM cypher('RecommenderSystem', $$
    MATCH (jurassic:Movie {title: 'Jurassic Park'}), (A:Category), (C:Category), (H:Category)
    WHERE A.name = 'Action' AND C.name = 'Comedy' AND H.name = 'Horror' 
    CREATE (jurassic)-[:RATING {rating: 1}]->(C),
           (jurassic)-[:RATING {rating: 3}]->(A),
           (jurassic)-[:RATING {rating: 0}]->(H)
$$) AS (a agtype);

-- Thor: Love and Thunder and it's relationship with Categories.
SELECT * FROM cypher('RecommenderSystem', $$
    MATCH (thor:Movie {title: 'Thor: Love and Thunder'}), (A:Category), (C:Category), (H:Category)
    WHERE A.name = 'Action' AND C.name = 'Comedy' AND H.name = 'Horror' 
    CREATE (thor)-[:RATING {rating: 4}]->(C),
           (thor)-[:RATING {rating: 2}]->(A),
           (thor)-[:RATING {rating: 0}]->(H)
$$) AS (a agtype);

-- The Matrix estimated rating for the user.
SELECT e1/(ct*4) AS factor FROM cypher('RecommenderSystem', $$
MATCH (u:Person)-[e1:RATING]->(v:Category)<-[e2:RATING]-(w:Movie{title: 'The Matrix'}), (c:Category) WITH e1, e2, COUNT(*) AS ct
RETURN SUM(e1.rating * e2.rating)::float, ct
$$) AS (e1 float, ct agtype);

      factor       
-------------------
 0.333333333333333
(1 row)

-- Shrek's estimated rating for the user.
SELECT e1/(ct*4) AS factor FROM cypher('RecommenderSystem', $$
MATCH (u:Person)-[e1:RATING]->(v:Category)<-[e2:RATING]-(w:Movie{title: 'Shrek'}), (c:Category) WITH e1, e2, COUNT(*) AS ct
RETURN SUM(e1.rating * e2.rating)::float, ct
$$) AS (e1 float, ct agtype);

      factor      
------------------
 1.16666666666667
(1 row)


-- The Blair Witch Project estimated rating for the user.
SELECT e1/(ct*4) AS factor FROM cypher('RecommenderSystem', $$
MATCH (u:Person)-[e1:RATING]->(v:Category)<-[e2:RATING]-(w:Movie{title: 'The Blair Witch Project'}), (c:Category) WITH e1, e2, COUNT(*) AS ct
RETURN SUM(e1.rating * e2.rating)::float, ct
$$) AS (e1 float, ct agtype);

 factor 
--------
 0.0
(1 row)


-- Jurassic Park estimated rating for the user.
SELECT e1/(ct*4) AS factor FROM cypher('RecommenderSystem', $$
MATCH (u:Person)-[e1:RATING]->(v:Category)<-[e2:RATING]-(w:Movie{title: 'Jurassic Park'}), (c:Category) WITH e1, e2, COUNT(*) AS ct
RETURN SUM(e1.rating * e2.rating)::float, ct
$$) AS (e1 float, ct agtype);
 factor 
--------
 0.5
(1 row)


-- Thor: Love and Thunder estimated rating for the user.
SELECT e1/(ct*4) AS factor FROM cypher('RecommenderSystem', $$
MATCH (u:Person)-[e1:RATING]->(v:Category)<-[e2:RATING]-(w:Movie{title: 'Thor: Love and Thunder'}), (c:Category) WITH e1, e2, COUNT(*) AS ct
RETURN SUM(e1.rating * e2.rating)::float, ct
$$) AS (e1 float, ct agtype);
      factor      
------------------
 1.16666666666667
(1 row)