This section introduces the gql() and gqlStream() methods on a Connection object for querying the database using GQL.

Each example focuses solely on the method's usage. For a complete code example, please refer to the full example.

GQL (Graph Query Language) is the ISO-standard query language for graph databases. For detailed information on GQL, refer to the documentation.

gql()

Executes a GQL query on the current graphset or the database and returns the result.

Parameters:

• string: The GQL query to be executed.
• RequestConfig (Optional): Configuration settings for the request.

Returns:

• Response: Result of the request.

// Retrieves 5 movie nodes in graphset 'miniCircle' and prints their information

let requestConfig = <RequestType.RequestConfig>{
  graphSetName: "miniCircle",
  useMaster: true,
};

let resp = await conn.gql(
  "MATCH (n:movie) RETURN n LIMIT 5",
  requestConfig
);

let node_list = resp.data?.get(0).asNodes();
node_list?.forEach((node) => {
  console.log(node.get("name"));
});

The Shawshank Redemption
Farewell My Concubine
Léon: The Professional
Titanic
Life is Beautiful

For more examples, please refer to Types Mapping Ultipa and Node.js.

gqlStream()

Executes a GQL query on the current graphset or the database and returns the result incrementally, allowing handling of large datasets without loading everything into memory at once.

Parameters:

• string: The GQL query to be executed.
• QueryResponseStream: Listener for the streaming process.
• RequestConfig (Optional): Configuration settings for the request.

Returns:

• void

// Retrieves all 1-step paths in graphset 'miniCircle'

RequestConfig requestConfig = new RequestConfig() { Graph = "miniCircle", UseMaster = true };

let count = 0;
let resp = await conn.gqlStream(
  "MATCH p = ()-[]-() RETURN p",
  {
    onData: async (res) => {
      let paths = res.data?.get(0).asPaths();
      count = count + (paths?.length || 0);
      console.log(count);
    },
    onEnd: () => {
      console.log("End");
    },
    onStart: () => {
      console.log("Start");
    },
    onError: (err) => {
      console.log(err);
    },
  },
  requestConfig
);

Start
Count =  1390
End

Full Example

import { ConnectionPool, printers } from "@ultipa-graph/ultipa-node-sdk5";
import { RequestType } from "@ultipa-graph/ultipa-node-sdk5/dist/types"; 


let sdkUsage = async () => {
  // Connection configurations
  // URI example: hosts="mqj4zouys.us-east-1.cloud.ultipa.com:60010"
  let hosts = [
    "192.168.1.85:60061",
    "192.168.1.86:60061",
    "192.168.1.87:60061",
  ];
  let username = "***";
  let password = "***";
  let connPool = new ConnectionPool(hosts, username, password);

  // Establishes connection to the database
  let conn = await connPool.getActive();
  let isSuccess = await conn.test();
  console.log(isSuccess);

  // Request configurations
  let requestConfig = <RequestType.RequestConfig>{
    graphSetName: "miniCircle",
    useMaster: true,
  };

  // Retrieves 10 nodes and prints the _id and name property value of the first returned one
  let resp = await conn.gql(
    "MATCH (n:movie) RETURN n LIMIT 10",
    requestConfig
  );

  let node_list = resp.data?.get(0).asNodes();
  if (node_list && node_list.length > 0) {
    console.log(node_list[0]._id, node_list[0].get("name"));
  }
};

sdkUsage().then(console.log).catch(console.log);