DataStax Enterprise 5.0+ now includes a graph-orient database. The DSE driver can execute graph queries written in the Gremlin language. Graph queries are executed using either the Session::executeGraph() and Session::executeGraphAsync() methods and return Graph\ResultSet objects which can represent Cassandra types or graph specific types (e.g. vertices and edges).

Graph Options

Graph options control how graph queries are run and can be specified when constructing a Dse\Cluster object or they can be specified per query. At a minimum, a graph name must be provide when running regular graph queries. Running system commands do not require specifying a graph name.

# Construct graph options with a graph name "users"
$graphOptions = Dse::graphOptions()

# Construct a new cluster object with specific graph options
$cluster = Dse::cluster()
$session = $cluster->connect();

# Execute a graph query using the cluster-level graph options
$resultset = $session->executeGraph("g.V().count()");

Graph options can also be specified (or overridden) when executing a query.

$cluster = Dse::cluster()->build();
$session = $cluster->connect();

$resultset = $session->executeGraph("g.V().count()", array("graph_name" => "users"));

Graph Results

A Dse\Graph\ResultSet object is returned from the graph execution methods. Resultsets are iterable and indexable list of Dse\Graph\Result objects. Dse\Graph\Result is an arbitrary data result and it can be various types from simple data types such as numbers and strings, composite data types such as arrays and dictionaries, as well as graph elements such as vertices and edges.

# A `Dse\Graph\Result can hold arbitrary data, in this case the number of
# vertices held by the graph.
$result = $session->execute("g.V().count()")->first();

echo "Vertex count: {$result->value()}" . PHP_EOL;


Vertices are graph elements connected by edges. They contain properties and unlike other graph elements (e.g. edges) vertex properties can contain multiple values and can have properties of their own.

$resultset = $session->executeGraph("g.V()");

foreach ($resultset as $result) {
  $vertex = $result->asVertex(); # Convert to vertex

  echo "Vertex label: {$vertex->id()['~label']}" . PHP_EOL;

  foreach($vertex->properties() as $property) {
    echo "Vertex property name: {$property->name()}" . PHP_EOL;
    # Each vertex property can contain multiple values
    foreach ($property->value() as $value) {
      echo "Vertex property value: {$value['value']}" . PHP_EOL;


Edges connected pairs of vertices. Like vertices they have properties, but they are simple key/value pairs.

$resultset = $session->executeGraph("g.E()");

foreach ($resultset as $result) {
  $edge = $result->asEdge();

  echo "Edge type: {$edge->id()['~type']}" . PHP_EOL;

  # Each edge has an input and output vertex
  echo "Edge incoming vertex label: {$edge->inVLabel()}" . PHP_EOL;
  echo "Edge outgoing vertex label: {$edge->outVLabel()}" . PHP_EOL;

  # Edge properties are simple key/value pairs
  foreach($edge->properties() as $property) {
    echo "Edge property name: {$property->name()}" . PHP_EOL;
    echo "Edge property value: {$property->value()}" . PHP_EOL;


Paths describe a list of graph elements that connect two vertices.

$resultset = $session->executeGraph("g.V().in().path()");

$path = $resultset->first()->asPath();

echo "Path labels: " . json_encode($path->labels()) . PHP_EOL;
echo "Length of path: " . count($path->labels()) . PHP_EOL;

$objects = $path->objects();
for ($i = 0; $i < count($objects); $i++) {
  try {
    $vertex = $objects[$i]->asVertex();
    echo "Object $i is a(n) " . get_class($vertex) . " with the value: " . $vertex->property('name')->value()[0]['value'] . PHP_EOL;
  } catch(Dse\Exception\DomainException $e) {
    $edge = $objects[$i]->asEdge();
    echo "Object $i is a(n) " . get_class($edge) . " with the value: " . $edge->label(). PHP_EOL;