Result Processing

The results from database read and write operations must be properly processed before being utilized in your application.

Return a Response

Methods such as gql() and uql() return a Response object. To serve the application, you need to first extract the DataItem from the Response object, and then transform it into an appropriate driver data class.

A Response object includes the following attributes:

Extract DataItem

To extract DataItem from a Response object, use the get() or alias() method.

A DataItem object includes the following attributes:

get()

Retrieves data by the alias index.

Parameters

• index: number: Index of the alias.

Returns

• DataItem: The returned data.

const response = await conn.gql("MATCH (n)-[e]->() RETURN n, e LIMIT 3");
console.log(response.get(0).alias);
console.log(response.get(0).type);
console.log(response.get(0).entities);

The GQL query returns two aliases (n, e), and the get() method gets the DataItem of the alias n at index 0.

n
2
[Node{uuid='72059793061183504', id='ULTIPA800000000000003B', schema='account', values={industry='Publishing', name='Velox', gender='female', year=1976}}, Node{uuid='648520545364606993', id='ULTIPA800000000000003E', schema='account', values={industry='Food&Beverage', name='Claire', gender='female', year=1989}}, Node{uuid='720578139402534937', id='ULTIPA8000000000000050', schema='account', values={industry='Education', name='Holly', gender='male', year=2000}}]

alias()

Retrieves data by the alias name.

Parameters

• alias: string: Name of the alias.

Returns

• DataItem: The returned data.

const response = await conn.gql("MATCH (n)-[e]->() RETURN n, e LIMIT 3");
console.log(response.alias("e").alias);
console.log(response.alias("e").type);
console.log(response.alias("e").entities);

The GQL query returns two aliases (n, e), and the alias() method gets DataItem of the alias e.

e
3
[Edge{uuid=139, fromUuid=6269012880322985990, toUuid=-7998395137233256453, from=ULTIPA800000000000000E, to=ULTIPA800000000000000D, schema=agree, values={targetPost=905, timestamp=1572662452, datetime=2018-10-14T06:27:42}}, Edge{uuid=378, fromUuid=72059793061183493, toUuid=8214567919347040275, from=ULTIPA800000000000003B, to=ULTIPA800000000000000F, schema=follow, values={}}, Edge{uuid=531, fromUuid=72059793061183493, toUuid=4827864298099310661, from=ULTIPA800000000000003B, to=ULTIPA80000000000003F4, schema=wishlist, values={toUuid=1012, uuid=1368, fromUuid=59, timestamp=Sat Mar 23 17:09:12 CST 2019, datetime=2019-03-23T17:09:12}}]

Transform DataItem

You should use a as<DataStructure>() method to convert the DataItem.entities into the corresponding driver data class.

For example, the GQL query contained in the request below retrieves 3 nodes from the graph, the asNodes() method is used to convert the DataItem associated with the alias n into a list of Node objects:

const response = await conn.gql("MATCH (n) RETURN n LIMIT 3");
const nodeList = response.alias("n").asNodes();
for (const node of nodeList) {
  console.log(node.id)
}

The following lists all the transformation methods available on DataItem. Please note the applicable DataItem.type and DataItem.alias of each method.

Return a ResponseWithExistCheck

Methods such as createGraphIfNotExist() return a ResponseWithExistCheck object.

A ResponseWithExistCheck object includes the following attributes:

Return an InsertResponse

Some data insertion methods such as insertNodesBatchBySchema() and insertNodesBatchAuto() return an InsertResponse object.

An InsertResponse object includes the following attributes:

Return a JobResponse

Methods such as createFulltext() return a JobResponse object.

A JobResponse object includes the following attributes:

Return Driver Data Classes

Some methods return either a single instance or a list of driver data class, which can be used directly. For example:

• The getGraph() method returns a single GraphSet object.
• The showGraph() method returns GraphSet[].