javascript-client.md

description
A very quick tutorial combining the individual elements of the JavaScript how-to guides to get you started.

JavaScript Client Tutorial

This guide demonstrates the basic use of the WOQLClient library to connect to TerminusDB with the JavaScript Client. Refer to TerminusDB JavaScript Client Reference Guide for detailed documentation.

{% hint style="info" %} The code discussed on this page is also available in full on GitHub - getting-started.js {% endhint %}

You can also find a comprehensive getting-started guide on GitHub: 5-Part JS Client Getting Started Guide.

Use a WOQLClient

Common uses of a WOQLClient include connecting to an existing database and creating a new database.

Install JavaScript Client

Connect to a database

Connect to an existing database using the example below.

{% tabs %} {% tab title="JavaScript" %}

client.db('ExampleDatabase');

{% endtab %} {% endtabs %}

Create a database

Create a new database using the example below.

{% tabs %} {% tab title="JavaScript" %}

const createNewDB = async () => {
  try {

      await client.createDatabase('ExampleDatabase', {
          label: "ExampleDatabase",
          comment: "Created new ExampleDatabase",
      });

      console.log("Database created Successfully!")c

  } catch (err) {
      console.error(err)
  }
};

createNewDB();

{% endtab %} {% endtabs %}

Basic Commands

Create a schema and add documents to the schema by using the document interface. Refer to the Document Interface Reference Guide for more detail. After creating or connecting to a database, create a schema to add and retrieve data. A simple player roster is used as an example. Using Player roster data, the steps below are demonstrated.

• Create a schema
• Add a schema
• Add documents
• Get documents
• Query documents

Data: Player roster

name   | position
------ | --------
George | Center Back
Doug   | Full Back
Karen  | Center Forward

Code: Create a schema

Create a schema object with properties name and position. The object is uniquely identified by name.

{% tabs %} {% tab title="JavaScript" %}

const schema = { "@type" : "Class",
                 "@id"   : "Player",
                 "@key"  : { "@type": "Lexical", "@fields": ["name"] },
                 name    : "xsd:string",
                 position: "xsd:string" };

{% endtab %} {% endtabs %}

Code: Add a schema

Add the schema object to the database.

{% tabs %} {% tab title="JavaScript" %} Add the schema object to a document using addDocument which returns a Promise.

await client.addDocument(schema, { graph_type: "schema" })

{% endtab %} {% endtabs %}

Code: Add documents

Once a schema is added, add documents corresponding to the schema.

{% tabs %} {% tab title="JavaScript" %} Add documents to the schema using addDocument which returns a Promise.

const objects = [
    {
        "@type" : "Player",
        name    : "George",
        position: "Center Back",
    },
    {
        "@type" : "Player",
        name    : "Doug",
        position: "Full Back",
    },
    { 
        "@type" : "Player", 
        name    : "Karen", 
        position: "Center Forward" 
    }
];
        
await client.addDocument(objects);

{% endtab %} {% endtabs %}

Code: Get documents

Get a list of documents or specific documents added to the schema

{% tabs %} {% tab title="JavaScript" %} Get a list of documents using getDocument as_list. Results, stored in document, are shown further below.

const getDocs = async () => {
  const documents = await client.getDocument({ as_list: "true" });
  console.log("All Documents", documents)
}

[
  {
    '@id'   : 'Player/Doug',
    '@type' : 'Player',
    name    : 'Doug',
    position: 'Full Back'
  },
  {
    '@id'   : 'Player/George',
    '@type' : 'Player',
    name    : 'George',
    position: 'Center Back'
  },
  {
    '@id'   : 'Player/Karen',
    '@type' : 'Player',
    name    : 'Karen',
    position: 'Center Forward'
  }
]

{% endtab %} {% endtabs %}

Code: Query documents

Get a list of documents that matches the query

{% tabs %} {% tab title="JavaScript" %} Get a list of documents using getDocument as_list. Results, stored in document, are shown further below.

const queryDocuments = async () => {
  const query = {
      "type": "Player",
      "query": { "position": "Full Back" },
     }
  const result = await client.queryDocument(query,{"as_list":true});
  console.log("Query Documents",result)
}

[{"@type" : "Player",
  "name" : "Doug",
  "position" : "Full Back"}]

{% endtab %} {% endtabs %}

Code: Query documents using WOQL

Query documents using Web Object Query Language (WOQL) to get the same result given by the above example. You can find more about WOQL here.

{% tabs %} {% tab title="JavaScript" %} Get documents using using WOQL.triple() to create a WOQL query then execute that query using client.query(). Results, stored in results, are shown further below

const queryDocuments = async () => {
  const { WOQL } = TerminusDBClient;
    const query = WOQL.triple(
      "v:Player",
      "position",
      WOQL.string("Full Back")
    ).triple("v:Player", "position", "v:position");
  const results = await client.query(query);
  console.log("Query Documents using WOQL: ",results.bindings);
}

[
  {
    Player: 'Player/Doug',
    position: { '@type': 'xsd:string', '@value': 'Full Back' }
  }
]

{% endtab %} {% endtabs %}

Create links between documents

The following code segments demonstrate creating relationships or links between documents

Code: Create schema for team

The Team object is uniquely identified by the property name. The players property consists of a set of Player classes that create a link between theTeam and Player schema.

{% tabs %} {% tab title="Javascript" %}

const team_schema = [
        {
            "@type" : "Class",
            "@id" : "Team",
            "@key" : { 
            "@type": "Lexical", 
            "@fields": ["name"] 
            },
            name : "xsd:string",
            players: { "@type" : "Set",
                       "@class" : "Player" },
        }
];

{% endtab %} {% endtabs %}

Code: Add a schema

Add the schema object to the database.

{% tabs %} {% tab title="JavaScript" %} Add the schema object to a document using addDocument that returns a Promise.

await client.addDocument(team_schema, { graph_type: "schema" })

{% endtab %} {% endtabs %}

Code: Add documents

Add documents corresponding to the Team schema.

{% tabs %} {% tab title="JavaScript" %}

const team_instance = [
        {
            "@type" : "Team",
            name    : "Wildcats",
            players: ["Player/Doug", "Player/Karen"],
        },
        {
            "@type" : "Team",
            name    : "Donkeys",
            players: ["Player/George"],
        }
    ]

await client.addDocument(team_instance)

{% endtab %} {% endtabs %}

Code: Get all of the teams

Get a list of Team documents.

{% tabs %} {% tab title="JavaScript" %}

const getTeams = async () => {
  const query = {
      "type": "Team",
  };
  const result = await client.queryDocument(query, {"as_list":true});
  console.log("Teams ",result)
}

{% endtab %} {% endtabs %}

See also

JavaScript Client Reference Guide

Getting Started with the JavaScript Client Tutorials