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: *configuration.RequestConfig (Optional): Request configuration.

Returns

• Response: Response of the request.
• error: An error object that contains details about any issues encountered during the operation. If the operation succeeds, nil is returned.

// Retrieves 5 movie nodes from the graph 'miniCircle'

requestConfig := &configuration.RequestConfig{
  Graph: "miniCircle",
}

response, _ := driver.Gql("MATCH (n:movie) RETURN n LIMIT 5", requestConfig)
nodeList, _, _ := response.Alias("n").AsNodes()
for _, node := range nodeList {
  fmt.Println(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: func(*http.Response) error: A callback function that processes the http.Response as it streams in. The function should return an error if something goes wrong during processing.
• config: *configuration.RequestConfig (Optional): Request configuration.

Returns

• error: An error object that contains details about any issues encountered during the operation. If the operation succeeds, nil is returned.

import (
    ...
	sdkhttp "github.com/ultipa/ultipa-go-sdk/sdk/http" // renamed to avoid conflict
    ...
)

...

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

requestConfig := &configuration.RequestConfig{
    Graph: "miniCircle",
}

fmt.Println("Stream started.")

cb := func(resp *sdkhttp.Response) error {
    // Print query statistics
    printers.PrintStatistics(resp.Statistic)

    // Try to parse response as paths (assuming RETURN p yields paths)
    paths, err := resp.Get(0).AsPaths()
    if err != nil {
        fmt.Println("Error parsing paths:", err)
        return err
    }

    for i, p := range paths {
        fmt.Printf("Path %d: %+v\n", i+1, p)
    }
    return nil
}

gql := "MATCH p = ()-[]-() RETURN p"
err = driver.GQLStream(gql, cb, requestConfig)
if err != nil {
    log.Fatalln("Stream error:", err)
}

fmt.Println("Stream ended.")

Stream started.
Total Cost : 0.67s | Engine Cost : 0s
Path 1: &{NodeUUIDs:[6196955286285058158 7998395137233256563] EdgeUUIDs:[2356] Nodes:map[6196955286285058158:0xc0009e7950 7998395137233256563:0xc0009e7ad0] Edges:map[2356:0xc00029e6e0]}
Path 2: &{NodeUUIDs:[6196955286285058158 9223377534412914884] EdgeUUIDs:[2524] Nodes:map[6196955286285058158:0xc0009e7e30 9223377534412914884:0xc000a14030] Edges:map[2524:0xc00029ed70]}
...
Path 237: &{NodeUUIDs:[18302634383191834827 17942343114467311744] EdgeUUIDs:[2633] Nodes:map[17942343114467311744:0xc0004d3a70 18302634383191834827:0xc0004d38c0] Edges:map[2633:0xc0005374f0]}
Stream ended.

Full Example

package main

import (
	"fmt"
	"log"

	"github.com/ultipa/ultipa-go-sdk/sdk"
	"github.com/ultipa/ultipa-go-sdk/sdk/configuration"
)

func main() {
	config := &configuration.UltipaConfig{
		// URI example:	Hosts: []string{"mqj4zouys.us-east-1.cloud.ultipa.com:60010"},
		Hosts:    []string{"192.168.1.85:60061", "192.168.1.87:60061", "192.168.1.88:60061"},
		Username: "<usernmae>",
		Password: "<password>",
	}

	driver, err := sdk.NewUltipaDriver(config)
	if err != nil {
		log.Fatalln("Failed to connect to Ultipa:", err)
	}

	// Retrieves 5 movie nodes from the graph 'miniCircle'

	requestConfig := &configuration.RequestConfig{
		Graph: "miniCircle",
	}

	response, _ := driver.Gql("MATCH (n:movie) RETURN n LIMIT 5", requestConfig)
	nodeList, _, _ := response.Alias("n").AsNodes()
	for _, node := range nodeList {
		fmt.Println(node.Get("name"))
	}
}