UQL Execution

This section introduces the uql() and uqlStream() methods on a Connection object for querying the database using UQL.

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

NOTE

UQL (Ultipa Query Language) is the language designed for fully interacting with Ultipa graph databases. For detailed information on UQL, refer to the documentation.

uql()

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

Parameters:

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

Returns:

• Response: Result of the request.

Java
// Retrieves 5 @movie nodes in graphset 'miniCircle' and prints their names

RequestConfig requestConfig = new RequestConfig();
requestConfig.setGraphName("miniCircle");

Response response = client.uql("find().nodes({@movie}) as n return n{*} limit 5", requestConfig);
List<Node> nodeList = response.alias("n").asNodes();
for (Node node : nodeList) {
    System.out.println(node.get("name"));
}

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

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

uqlStream()

Executes a UQL 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 UQL query to be executed.
• UqlListener: Listener for the streaming process.
• RequestConfig (Optional): Configuration settings for the request.

Returns:

• void

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

RequestConfig requestConfig = new RequestConfig();
requestConfig.setGraphName("miniCircle");

client.uqlStream("n().e().n() as paths return paths{*}", new UqlListener() {
    int count = 0;

    public void onReady() {
        System.out.println("Start downloading");
    }

    public void next(Response response) {
        if (response.getStatus().getErrorCode() != Ultipa.ErrorCode.SUCCESS){
            System.out.println(response.getStatus().getMsg());
        }
        List<Path> paths = response.get(0).asPaths();
        count += paths.size();
        System.out.println("count = " + count);
    }

    public void onComplete() {
        System.out.println("Done");
        System.out.println("count = " + count);
    }

    public void onError(Throwable throwable) {
        System.out.println("Error");

    }
}, requestConfig);

Output
count = 1250
count = 1392
Done
count = 1392

Full Example

Main.java
package com.ultipa.www.sdk.api;

import com.ultipa.sdk.connect.Connection;
import com.ultipa.sdk.connect.conf.RequestConfig;
import com.ultipa.sdk.connect.conf.UltipaConfiguration;
import com.ultipa.sdk.connect.driver.UltipaClientDriver;
import com.ultipa.sdk.operate.entity.*;
import com.ultipa.sdk.operate.response.Response;
import java.util.*;

public class Main {
    public static void main(String[] args) {
         // Connection configurations
        UltipaConfiguration myConfig = UltipaConfiguration.config()
            // URI example: .hosts("mqj4zouys.us-east-1.cloud.ultipa.com:60010")
            .hosts("192.168.1.85:60061,192.168.1.86:60061,192.168.1.87:60061")
            .username("<username>")
            .password("<password>");

        UltipaClientDriver driver = null;
        try {
            // Establishes connection to the database
            driver = new UltipaClientDriver(myConfig);
            Connection client = driver.getConnection();
          
            // Request configurations
            RequestConfig config = new RequestConfig();
            config.setGraphName("amz");
            
            // Retrieves 10 nodes and prints the _id and storeName property value of the first returned one
            Response response = client.uql("find().nodes() as n return n{*} limit 10", config);
            List<Node> nodeList = response.alias("n").asNodes();
            System.out.println("ID of the 1st node: " + nodeList.get(0).getID());
            System.out.println("Store name of the 1st node: " + nodeList.get(0).get("storeName"));
        } finally {
            if (driver != null) {
                driver.close();
            }
        }
    }
}