Templatize Gremlin request parameters

FAQ

• Internal reserved words

  • In property(id, G__id), the unquoted id is the primary key and must satisfy the global uniqueness constraint.

  • When you set parameter bindings, do not use the format g.addV(label).property('id', id). Both `id` and `label` are internal reserved words. In the statement, the quoted 'id' represents a regular property and does not satisfy the uniqueness constraint.

• Limit on the number of templatized parameters

  GDB supports a maximum of 128 templatized parameters in `bindings`. This limit cannot be changed.

• Selecting parameters to templatize

  When a script request is used in a fixed scenario, only some data parameters are variable. You can create placeholders only for the variable parts. You can hard-code fixed data directly into the request.

  The following example request adds a vertex with the label 'person' and two properties: 'name' and 'age'.

  dsl = "g.addV('person').property('name', G___PV1).property('age', G___PV2)"
  
  bindings = {"G___PV1":"Jack","G___PV2":29}
  client.submit(dsl, bindings).all().join()

  The `dsl` parameter remains unchanged. You can fill the `bindings` map with the retrieved 'name' and 'age' data and submit the request to write the vertex data.

• List parameter support

  // For list types, such as hasId and within, and for valueMap as shown below, use multiple placeholders.
  String dsl = "g.V().has(G__key1, within(G__value1)).valueMap(true)";
  Map<String, Object> parameters= new HashMap<>(1);
  List<String> values = new ArrayList<>(Arrays.asList("beijing", "shanghai", "shenzhen"));
  parameters.put("G__key1", "location");
  parameters.put("G__value1", values);
  List<Result> result = client.submit(dsl, parameters).all().join();

  Some Gremlin Step parameters, such as `ValueMap`, do not support array-type parameters. You can use multiple placeholders to specify each element in the multi-value type.

  # The valueMap parameter does not support arrays. This causes a parameter error.
  bindings = {"G___PKs":["name","age"]}
  dsl = "g.V().hasLabel('person').valueMap(G___PKs)"
  client.sumbit(dsl, bindings)
  
  # Use two placeholders to represent the two parameters. This is correct.
  bindings = {"G___PK1":"name","G___PK2":"age"}
  dsl = "g.V().hasLabel('person').valueMap(G___PK1,G___PK2)"
  client.submit(dsl, bindings).all().join()

Java parameter templatization

String dsl ="g.addV(G___label).property(id,G___id).property('name',G___name)";

Map<String, Object> parameters = new HashMap<>();
parameters.put("G___id","sand131_id_5_99"); // Vertex ID parameter
parameters.put("G___label","person");       // Vertex label parameter
parameters.put("G___name","Jack");          // Value parameter for the 'name' property of the vertex

List<Result> result = client.submit(dsl, parameters).all().join();

Python parameter templatization

dsl ="g.addV(G___label).property(id,G___id).property('name',G___name)"

parameters = {}
parameters["G___id"] = "sand131_id_5_99"
parameters["G___label"] = "person"
parameters["G___name"] = "Jack"

results = client.submit(dsl, bindings=parameters).all().result()

.NET parameter templatization

string dsl ="g.addV(G___label).property(id,G___id).property('name',G___name)";
Dictionary<string, object> parameters = new Dictionary<string, object> {
                    {"G___id", "sand131_id_5_99"},
                    {"G___label", "person"},
                    {"G___name", "Jack"}};

gremlinClient.SubmitAsync<dynamic>(dsl, parameters);

Node.js parameter templatization

function addVertex1()
{
    return client.submit("g.addV(G___label).property(id,G___id).property('name',G___name)",{
        G___id: "sand131_id_5_99",
        G___label: "person",
        G___name: "Jack"
    }).then(data => {
        console.log("Add Vertex Result: %s\n", JSON.stringify(data));
    });
}

Go parameter templatization

dsl := "g.addV(G___label).property(id,G___id).property('name',G___name)"
parameters := make(map[string]interface{})
parameters["G___id"] = "sand131_id_5_99"
parameters["G___label"] = "person"
parameters["G___name"] = "Jack"

results, err := client.SubmitScriptBound(dsl, parameters)