opencypher.org

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12 Person Person Director name: Ed Jones age: 37 favcolor: blue FRIENDS since: qualified: good name: Peter Fry nick: Lil Pete bio:...

13 MATCH (me:person)-[:friend]->(friend) WHERE me.name = "Frank Black" AND friend.age > me.age RETURN friend.name, friend.title CREATE (you:person) SET you.name = "Aaron Fletcher" CREATE (you)-[:friend]->(me) MATCH (me:person{name:$name})-[:friend]-(friend) WITH me, count(friend) AS friends MATCH (me)-[:enemy]-(enemy) RETURN friends, count(enemy) AS enemies

14 MATCH (), (node), (node:node), (:Node), (node {type:"node"}) MATCH ()-->(), ()-[edge]->(), ()-[edge:relates]->(), ()-[:RELATES]->(), ()-[edge {score:5}]->(), (a)-[edge]->(b) (a)<-[edge]-(b), (a)-[edge]-(b) MATCH p = (a)-[:one]-()-[:two]-()-[:three]-() MATCH p = (me)-[:friend*]-(foaf) MATCH (me)-[:friend*1..3]-(foaf)

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16 <outer-query> { <inner-query> } <next-outer-query> (continued)

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19 MATCH (actor:actor) WHERE EXISTS { MATCH(other:Actor)-[:ACTED_IN]->(movie)<-[:ACTED_IN]-(actor) WHERE other.name = actor.name } RETURN actor

20 MATCH (dtor:director) WHERE dtor.age < SCALAR { MATCH (dtor)-[:directed]->(m:movie), (a:actor)-[:acted_in]->(m) RETURN min(a.age) } RETURN dtor.name AS young_director

21 ... WITH... AS my_list RETURN [ UNWIND my_list AS item WHERE item.size < 15 RETURN item ] AS small_items

22 <inner-query>... RETURN <inner-query> { }

23 MATCH { // authored tweets MATCH (me:user {name: 'Alice'})-[:FOLLOWS]->(user:User), (user)<-[:authored]-(tweet:tweet) RETURN tweet, tweet.time AS time, user.country AS country UNION // favorited tweets MATCH (me:user {name: 'Alice'})-[:FOLLOWS]->(user:User), (user)<-[:has_favourite]-(favorite:favorite)-[:targets]->(tweet:tweet) RETURN tweet, favourite.time AS time, user.country AS country } WHERE country = 'se' RETURN DISTINCT tweet ORDER BY time DESC

24 MATCH (u:user {id: $userid}) MATCH (f:farm {id: $farmid})-[:is_in]->(country:country) MATCH { MATCH (u)-[:likes]->(b:brand)-[:produces]->(p:lawnmower) RETURN b.name AS name UNION MATCH (u)-[:likes]->(b:brand)-[:produces]->(v:vehicle) WHERE v.lefthanddrive = country.lefthanddrive RETURN b.name AS name } RETURN f, name

25 MANDATORY OPTIONAL MATCH MANDATORY MATCH (p:person {name: 'Petra'}) MANDATORY MATCH (conf:conference {name: $conf}) MANDATORY MATCH { MATCH (p)-[:attends]->(conf) RETURN conf } OPTIONAL MATCH { MATCH (p)-[:knows]->(a:attendee)-[:published_at]->(conf) RETURN a.name AS name } RETURN name

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28 Graph => CYPHER 9 => Table CYPHER 9 = Clause Clause Clause... RETURN *

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30 WITH * WITH val res1 = cypher("match (a)-[r]->(b) RETURN *") val res2 = res1.cypher(" WITH a, r, b MATCH (b)-->(c) RETURN DISTINCT c")

31 Table => CYPHER => Table => CYPHER =>... MATCH (a) MATCH { MATCH (a)-->(b) RETURN * } WITH * // keep going...

32 Graph => CYPHER => Graph => CYPHER =>... Graph Table => CYPHER => Graph Table => CYPHER =>...

33 Graph Transformation

34 Why Multiple Graphs? - Combining and transforming graphs from multiple sources - Versioning, snapshotting, computing difference graphs - Graph views for access control - Provisioning applications with tailored graph views - Shaping and integrating heterogenous graph data - Roll-up and drill-down at different levels of detail Graph Management Graph Modeling

35 Cypher today: Single graph model Graph Database System (e.g. a cluster) Application Server Client 1 Client 2 Client 3 The (single) Graph

36 Cypher: Multiple graphs model Graph Database System (e.g. a cluster) Application Server Client 1 Client 2 Client 3 Graph Space

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38 Tables from graphs... It's easy to construct tables from a graph... but what's the inverse? MATCH (a)-->(b) WITH a, b...

39 ...graphs from tables...a graph is a set of pattern matches! WITH a, r, b RETURN GRAPH OF (a)-[r]->(b) AS foo

40 Current CAPS Multiple Graphs Syntax FROM GRAPH graph_a AT "bolt://.../people" MATCH (a:person)-[:knows]-(b:person) FROM GRAPH graph_b AT "hdfs://.../products" MATCH (:Customer {name: a.name})-[:bought]->(p:product) RETURN GRAPH OF (b)-[:should_buy]->(p) (Ongoing work in CIP : Multiple Graphs)

41 Cypher queries with multiple graphs

42 Cypher query pipeline composition

43 Cypher support for multiple graphs - Graphs are addressed using URIs Graphs and tabular data are passed into and returned from a query Extensions - Set operations and subqueries over multiple graphs Updating graphs (DML) Managing graph persistence (Move, Snapshot, Version,...) Creating views Schema and constraint definitions for multiple graphs... => Join the opencypher MG Task Force

44 All this is made available in (:Cypher)-[:FOR]->(:Apache:Spark) github.com/opencypher/cypher-for-apache-spark

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47 ε G = {(v,v) v V} _ G = {(v,w) (v,a,w) E a} a G = {(v,w) (v,a,w) E} a- G = {(v,w) (w,a,v) E} ɑ* G = ɑ G G G ɑ β = ɑ β ɑ β G = ɑ G β G ɑ G = V V - ɑ G [φ] G = {(v,v) v φ G} ɑn,m G = k=nm( ɑ G)k ɑ= G = {(v,w) ɑ= G ρ(v)=ρ(w)} ɑ G = {(v,w) ɑ= G ρ(v) ρ(w)} ɑ β G = ɑ G β G

48 grouped Edge label direction Edge label MATCH (actor)-/[:acted_in> <:ACTED_IN]+/-(bacon) repeated WHERE bacon.name = "Kevin Bacon"

49 ()-/ ()-/ ()-/ ()-/ ()-/ ()-/ ()-/ ()-/ ()-/ ()-/ :FOO /-() (:Something) /-() [-{val:5}] /-() ({key:"a"}) /-() - /-() :FIRST :SECOND /-() :ONE :ANOTHER /-() [:A :B] [:B :A] /-() :A* :B+ :C*2..5 /-() :A> <:B <:C> /-()

50 PATH PATTERN older_friends = (a)-[:friend]-(b) WHERE b.age > a.age MATCH p = (me)-/ ~older_friends + /-(you) WHERE me.name = $myname AND you.name = $yourname RETURN p AS friendship

51 PATH PATTERN older_friends = (a)-[:friend]-(b) WHERE b.age > a.age PATH PATTERN same_city = (a)-[:lives_in]->(:city)<-[:lives_in]-(b) PATH PATTERN older_friends_in_same_city = (a)-/ ~older_friends /-(b) WHERE EXISTS { (a)-/ ~same_city /-(b) }

52 []. () [...] [^...]

53 PATH PATTERN road = (a)-[r:road_segment]-(b) COST r.length MATCH route = (start)-/ ~road * /-(end) WHERE start.location = $currentlocation AND end.name = $destination ORDER BY cost(route) ASC LIMIT 3 RETURN route

54 PATH PATTERN influential_friends = (a)-[:knows]-(b), (a)-[:sent]->(msg), (b)-[:received]->(msg) COST 1 / count(msg) MATCH p = (me)-/ ~influential_friends * /-(them) WHERE me.name = $myname AND them.name IN $names ORDER BY cost(p) ASC LIMIT 10 RETURN nodes(p)[1] AS target

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