GQL Execution

This section introduces the gql() and gqlStream() methods to execute GQL in the database.

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 in the database.

Parameters

• gql: string: The GQL query to be executed.
• config: RequestConfig (Optional): Request configuration.

Returns

• Response: Response of the request.

// Retrieves 5 movie nodes from the graph 'miniCircle' and prints their names

const requestConfig: RequestConfig = {
  graph: "miniCircle",
};

let response = await conn.gql(
  "MATCH (n:movie) RETURN n LIMIT 5",
  requestConfig
);
const nodeList = response.items?.get("n")?.asNodes();
nodeList?.forEach((node) => {
  console.log(node.get("name"));
});

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

gqlStream()

Executes a GQL query in the database and returns the results incrementally, allowing handling of large datasets without loading everything into memory at once.

Parameters

• gql: string: The GQL query to be executed.
• cb: RequestType.QueryResponseListener: Listener for the streaming process.
• config: RequestConfig (Optional): Request configuration.

Returns

• void

// Retrieves all 1-step paths from the graph 'miniCircle'

const requestConfig: RequestConfig = {
  graph: "miniCircle",
};

let count = 0;
let response = await conn.gqlStream(
  "MATCH p = ()-[]-() RETURN p",
  // Define the event handler functions
  {
      onStart: () => {
          console.log("Stream started.")
      },
      onData: async (res) => {
          let paths = res.items?.get("p")?.asPaths();
          count = count + (paths?.length || 0);
          console.log(count);
      },
      onEnd: () => {
          console.log("Stream ended.");
      },
      onError: (err) => {
          console.log(err);
      }
  },
  requestConfig
);

Stream started.
1024
2048
3072
3227
3464
3895
Stream ended.

Full Example

import { ConnectionPool } from "@ultipa-graph/ultipa-driver";
import { ULTIPA } from "@ultipa-graph/ultipa-driver/dist/types";

let sdkUsage = async () => {
  // URI example: ultipaConfig.hosts: ["mqj4zouys.us-east-1.cloud.ultipa.com:60010"]
  const ultipaConfig: ULTIPA.UltipaConfig = {
    hosts: ["192.168.1.85:60061", "192.168.1.87:60061", "192.168.1.88:60061"],
    username: "<username>",
    password: "<password>"
  };

  const conn = await new ConnectionPool(
    ultipaConfig.hosts,
    ultipaConfig.username,
    ultipaConfig.password
  ).getActive();
  const isSuccess = await conn.test();
  console.log(`Connection succeeds: ${isSuccess}`);

  // Retrieves 5 movie nodes from the graph 'miniCircle' and prints their names

  const requestConfig: ULTIPA.RequestConfig = {
    graph: "miniCircle",
  };
  const response = await conn.gql(
    "MATCH (n:movie) RETURN n LIMIT 5",
    requestConfig
  );
  let nodeList = response.items?.get("n")?.asNodes();
  nodeList?.forEach((node) => {
    console.log(node.get("name"));
  });
};
sdkUsage().catch(console.error);