--step 1
-- Create a GraphDemo database
IF NOT EXISTS (SELECT * FROM sys.databases WHERE NAME = 'graphdemo')
CREATE DATABASE GraphDemo;
GO
USE GraphDemo;
GO
-- Create NODE tables
CREATE TABLE Person (
ID INTEGER PRIMARY KEY,
name VARCHAR(100)
) AS NODE;
CREATE TABLE Restaurant (
ID INTEGER NOT NULL,
name VARCHAR(100),
city VARCHAR(100)
) AS NODE;
CREATE TABLE City (
ID INTEGER PRIMARY KEY,
name VARCHAR(100),
stateName VARCHAR(100)
) AS NODE;
-- Create EDGE tables.
CREATE TABLE likes (rating INTEGER) AS EDGE;
CREATE TABLE friendOf AS EDGE;
CREATE TABLE livesIn AS EDGE;
CREATE TABLE locatedIn AS EDGE;
--step 2
-- Insert data into node tables. Inserting into a node table is same as inserting into a regular table
INSERT INTO Person (ID, name)
VALUES (1, 'John')
, (2, 'Mary')
, (3, 'Alice')
, (4, 'Jacob')
, (5, 'Julie');
INSERT INTO Restaurant (ID, name, city)
VALUES (1, 'Taco Dell','Bellevue')
, (2, 'Ginger and Spice','Seattle')
, (3, 'Noodle Land', 'Redmond');
INSERT INTO City (ID, name, stateName)
VALUES (1,'Bellevue','WA')
, (2,'Seattle','WA')
, (3,'Redmond','WA');
-- Insert into edge table. While inserting into an edge table,
-- you need to provide the $node_id from $from_id and $to_id columns.
/* Insert which restaurants each person likes */
INSERT INTO likes
VALUES ((SELECT $node_id FROM Person WHERE ID = 1), (SELECT $node_id FROM Restaurant WHERE ID = 1), 9)
, ((SELECT $node_id FROM Person WHERE ID = 2), (SELECT $node_id FROM Restaurant WHERE ID = 2), 9)
, ((SELECT $node_id FROM Person WHERE ID = 3), (SELECT $node_id FROM Restaurant WHERE ID = 3), 9)
, ((SELECT $node_id FROM Person WHERE ID = 4), (SELECT $node_id FROM Restaurant WHERE ID = 3), 9)
, ((SELECT $node_id FROM Person WHERE ID = 5), (SELECT $node_id FROM Restaurant WHERE ID = 3), 9);
/* Associate in which city live each person*/
INSERT INTO livesIn
VALUES ((SELECT $node_id FROM Person WHERE ID = 1), (SELECT $node_id FROM City WHERE ID = 1))
, ((SELECT $node_id FROM Person WHERE ID = 2), (SELECT $node_id FROM City WHERE ID = 2))
, ((SELECT $node_id FROM Person WHERE ID = 3), (SELECT $node_id FROM City WHERE ID = 3))
, ((SELECT $node_id FROM Person WHERE ID = 4), (SELECT $node_id FROM City WHERE ID = 3))
, ((SELECT $node_id FROM Person WHERE ID = 5), (SELECT $node_id FROM City WHERE ID = 1));
/* Insert data where the restaurants are located */
INSERT INTO locatedIn
VALUES ((SELECT $node_id FROM Restaurant WHERE ID = 1), (SELECT $node_id FROM City WHERE ID =1))
, ((SELECT $node_id FROM Restaurant WHERE ID = 2), (SELECT $node_id FROM City WHERE ID =2))
, ((SELECT $node_id FROM Restaurant WHERE ID = 3), (SELECT $node_id FROM City WHERE ID =3));
/* Insert data into the friendOf edge */
INSERT INTO friendOf
VALUES ((SELECT $NODE_ID FROM Person WHERE ID = 1), (SELECT $NODE_ID FROM Person WHERE ID = 2))
, ((SELECT $NODE_ID FROM Person WHERE ID = 2), (SELECT $NODE_ID FROM Person WHERE ID = 3))
, ((SELECT $NODE_ID FROM Person WHERE ID = 3), (SELECT $NODE_ID FROM Person WHERE ID = 1))
, ((SELECT $NODE_ID FROM Person WHERE ID = 4), (SELECT $NODE_ID FROM Person WHERE ID = 2))
, ((SELECT $NODE_ID FROM Person WHERE ID = 5), (SELECT $NODE_ID FROM Person WHERE ID = 4));
--step 3
-- Find Restaurants that John likes
SELECT Restaurant.name
FROM Person, likes, Restaurant
WHERE MATCH (Person-(likes)->Restaurant)
AND Person.name = 'John';
-- Find Restaurants that John's friends like
SELECT Restaurant.name
FROM Person person1, Person person2, likes, friendOf, Restaurant
WHERE MATCH(person1-(friendOf)->person2-(likes)->Restaurant)
AND person1.name='John';
-- Find people who like a restaurant in the same city they live in
SELECT Person.name
FROM Person, likes, Restaurant, livesIn, City, locatedIn
WHERE MATCH (Person-(likes)->Restaurant-(locatedIn)->City AND Person-(livesIn)->City);
--step 4
-- Find friends-of-friends-of-friends, excluding those cases where the relationship "loops back".
-- For example, Alice is a friend of John; John is a friend of Mary; and Mary in turn is a friend of Alice.
-- This causes a "loop" back to Alice. In many cases, it is necessary to explicitly check for such loops and exclude the results.
SELECT CONCAT(Person.name, '->', Person2.name, '->', Person3.name, '->', Person4.name)
FROM Person, friendOf, Person as Person2, friendOf as friendOffriend, Person as Person3, friendOf as friendOffriendOfFriend, Person as Person4
WHERE MATCH (Person-(friendOf)->Person2-(friendOffriend)->Person3-(friendOffriendOfFriend)->Person4)
AND Person2.name != Person.name
AND Person3.name != Person2.name
AND Person4.name != Person3.name
AND Person.name != Person4.name;
