arangodb/Documentation/Books/Drivers/java-reference-graph.md

layout	description
default	These functions implement theHTTP API for manipulating graphs

Graph API

These functions implement the HTTP API for manipulating graphs.

ArangoDatabase.createGraph

ArangoDatabase.createGraph(String name, Collection<EdgeDefinition> edgeDefinitions, GraphCreateOptions options) : GraphEntity

Create a new graph in the graph module. The creation of a graph requires the name of the graph and a definition of its edges.

Arguments

• name: String

  Name of the graph

• edgeDefinitions: Collection<EdgeDefinition>

  An array of definitions for the edge

• options: GraphCreateOptions

  • orphanCollections: String...

    Additional vertex collections

  • isSmart: Boolean

    Define if the created graph should be smart. This only has effect in Enterprise Edition.

  • replicationFactor: Integer

    (The default is 1): in a cluster, this attribute determines how many copies of each shard are kept on different DBServers. The value 1 means that only one copy (no synchronous replication) is kept. A value of k means that k-1 replicas are kept. Any two copies reside on different DBServers. Replication between them is synchronous, that is, every write operation to the "leader" copy will be replicated to all "follower" replicas, before the write operation is reported successful. If a server fails, this is detected automatically and one of the servers holding copies take over, usually without an error being reported.

  • numberOfShards: Integer

    The number of shards that is used for every collection within this graph. Cannot be modified later.

  • smartGraphAttribute: String

    The attribute name that is used to smartly shard the vertices of a graph. Every vertex in this Graph has to have this attribute. Cannot be modified later.

Examples

ArangoDB arango = new ArangoDB.Builder().build();
ArangoDatabase db = arango.db("myDB");

EdgeDefinition edgeDefinition = new EdgeDefinition()
                                  .collection("edges")
                                  .from("start-vertices")
                                  .to("end-vertices");
GraphEntity graph = db.createGraph(
  "some-graph", Arrays.asList(edgeDefinition), new GraphCreateOptions()
);
// graph now exists

ArangoGraph.create

ArangoGraph.create(Collection<EdgeDefinition> edgeDefinitions, GraphCreateOptions options) : GraphEntity

Create a new graph in the graph module. The creation of a graph requires the name of the graph and a definition of its edges.

Alternative for ArangoDatabase.createGraph.

Arguments

• edgeDefinitions: Collection<EdgeDefinition>

  An array of definitions for the edge

• options: GraphCreateOptions

  • orphanCollections: String...

    Additional vertex collections

  • isSmart: Boolean

    Define if the created graph should be smart. This only has effect in Enterprise Edition.

  • replicationFactor: Integer

    (The default is 1): in a cluster, this attribute determines how many copies of each shard are kept on different DBServers. The value 1 means that only one copy (no synchronous replication) is kept. A value of k means that k-1 replicas are kept. Any two copies reside on different DBServers. Replication between them is synchronous, that is, every write operation to the "leader" copy will be replicated to all "follower" replicas, before the write operation is reported successful. If a server fails, this is detected automatically and one of the servers holding copies take over, usually without an error being reported.

  • minReplicationFactor: Integer

    (optional, default is 1): in a cluster, this attribute determines how many copies of each shard are required to be in sync on the different DBServers. If we have less then these many copies in the cluster a shard will refuse to write. The minReplicationFactor can not be larger than replicationFactor. Please note: during server failures this might lead to writes not being possible until the failover is sorted out and might cause write slow downs in trade of data durability.

  • numberOfShards: Integer

    The number of shards that is used for every collection within this graph. Cannot be modified later.

  • smartGraphAttribute: String

    The attribute name that is used to smartly shard the vertices of a graph. Every vertex in this Graph has to have this attribute. Cannot be modified later.

Examples

ArangoDB arango = new ArangoDB.Builder().build();
ArangoDatabase db = arango.db("myDB");

ArangoGraph graph = db.graph("some-graph");
EdgeDefinition edgeDefinition = new EdgeDefinition()
                                  .collection("edges")
                                  .from("start-vertices")
                                  .to("end-vertices");
graph.create(Arrays.asList(edgeDefinition), new GraphCreateOptions());
// graph now exists

ArangoGraph.exists

ArangoGraph.exists() : boolean

Checks whether the graph exists

Examples

ArangoDB arango = new ArangoDB.Builder().build();
ArangoDatabase db = arango.db("myDB");

ArangoGraph graph = db.graph("some-graph");
boolean exists = graph.exists();

ArangoGraph.getInfo

ArangoGraph.getInfo() : GraphEntity

Retrieves general information about the graph.

Examples

ArangoDB arango = new ArangoDB.Builder().build();
ArangoDatabase db = arango.db("myDB");

ArangoGraph graph = db.graph("some-graph");
GraphEntity info = graph.getInfo();

ArangoGraph.drop

ArangoGraph.drop(boolean dropCollections) : void

Deletes the graph from the database.

Arguments

• dropCollections: boolean

  Drop collections of this graph as well. Collections will only be dropped if they are not used in other graphs.

Examples

ArangoDB arango = new ArangoDB.Builder().build();
ArangoDatabase db = arango.db("myDB");

ArangoGraph graph = db.graph("some-graph");
graph.drop();
// the graph "some-graph" no longer exists