nogdb.js

Node.js bindings to the NogDB library

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Installation

We rely on node-gyp.

How to install

• first step : Install NogDB library.
• second step : Clone repo and npm install.

git clone https://github.com/nogdb/nogdb.js.git
cd nogdb.js
npm install

[Note] : You need python2.7 for node-gyp

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How to use

• First step In file javascript require nogdb in this form.

const nogdb = require("./build/Release/nogdb_js");

• Second step you must be create Database Context before use another function like this.

// "mygraph.db" is database path.
const ctx = new nogdb.Context("mygraph.db");

• Third step And create Transaction for use Database operations like this.

// Transaction has 2 mode "READ_WRITE" for modifired database and "READ_ONLY" can't modified database
var txn = new nogdb.Txn(ctx,"READ_WRITE");

In "READ_WRITE" mode you can call txn.commit(); after complete the transaction for affect to database.

• Fourth step you can use Database operations .

  • Class Operations from nogdb.Class

  • Property Operations from nogdb.Property

  • Database Operations from nogdb.Db

  • Vertex Operations from nogdb.Vertex

  • Edge Operations from nogdb.Edge

  • Traverse (Graph) Operations from nogdb.Traverse

See more Document

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Examples using nogdb.js

• Create classes VERTEX Words for words, VERTEX InitialWords for starting words and EDGE WordLinks for linking words

	const nogdb = require("./build/Release/nogdb_js");
// Create database context pointing to file 'mygraph.db'
	const ctx = new nogdb.Context("mygraph.db");
// Create READ_WRITE transaction
	var txn = new nogdb.Txn(ctx,"READ_WRITE");
// Create vertex 'Words'
	nogdb.Class.create(txn,"Words","VERTEX");
// Create vertex 'InitialWords'
	nogdb.Class.createExtend(txn,"InitialWords","Words");
// Create edge 'WordLinks'
	nogdb.Class.create(txn,"WordLinks","EDGE");

• Create Property messaged within VERTEX Words

	const nogdb = require("./build/Release/nogdb_js");
	const ctx = new nogdb.Context("mygraph.db");
	var txn = new nogdb.Txn(ctx,"READ_WRITE");

// create property 'string' within vertex 'Words' (also applied to 'InitialWords')
	nogdb.Property.add(txn, "Words", "messaged", "TEXT");

• Create vertices for InitialWords and Words. And create link between them.

	const nogdb = require("./build/Release/nogdb_js");
	const ctx = new nogdb.Context("mygraph.db");
	var txn = new nogdb.Txn(ctx,"READ_WRITE");

// Create prototypes of vertices
	hello = new nogdb.Record();
	world = new nogdb.Record();
	hello.set("messaged", "Hello");
	world.set("messaged", ", World.");
// Create vertices to db with created prototypes
	vHello = nogdb.Vertex.create(txn, "InitialWords", hello);
	vWorld = nogdb.Vertex.create(txn, "Words", world);
// Create link between both vertices
	nogdb.Edge.create(txn, "WordLinks", vHello, vWorld);
// Do a transaction commit
	txn.commit();

• Get Initial Word, go to another word through edge, print string for every word passed.

	const nogdb = require("./build/Release/nogdb_js");
	const ctx = new nogdb.Context("mygraph.db");

// Create READ_ONLY transaction
	var txn = new nogdb.Txn(ctx,"READ_ONLY");
// Get initial word from 'InitialWords'
	word1 = nogdb.Vertex.get(txn, "InitialWords");
// Get property 'string' from vertex and print to screen
	str_vertex = word1[0].record.value.messaged.toText;
// Get out edge from record
	edge = nogdb.Vertex.getOutEdge(txn,word1[0].recordDescriptor);
// Get destination vertex from edge
	word2 = nogdb.Edge.getDst(txn,edge[0].recordDescriptor);
// Get property 'string' from another vertex and print to screen
	str_another = word2.record.value.messaged.toText;
// Print show result
	console.log(str_vertex + str_another);

• This is what final hello_world.js looks like

// hello_world.js
const nogdb = require("./build/Release/nogdb_js");

// Create database context pointing to file 'mygraph.db'
	const ctx = new nogdb.Context("mygraph.db");

	 /* Write data */
// Create READ_WRITE transaction
	var txn = new nogdb.Txn(ctx,"READ_WRITE");
// Create vertex 'Words'
	nogdb.Class.create(txn,"Words","VERTEX");
// Create vertex 'InitialWords'
	nogdb.Class.createExtend(txn,"InitialWords","Words");
// Create edge 'WordLinks'
	nogdb.Class.create(txn,"WordLinks","EDGE");
// create property 'string' within vertex 'Words' (also applied to 'InitialWords')
	nogdb.Property.add(txn, "Words", "messaged", "TEXT");
// Create prototypes of vertices
	hello = new nogdb.Record();
	world = new nogdb.Record();
	hello.set("messaged", "Hello");
	world.set("messaged", ", World.");
// Create vertices to db with created prototypes
	vHello = nogdb.Vertex.create(txn, "InitialWords", hello);
	vWorld = nogdb.Vertex.create(txn, "Words", world);
// Create link between both vertices
	nogdb.Edge.create(txn, "WordLinks", vHello, vWorld);
// Do a transaction commit
	txn.commit();

	/* Read data */
// Create READ_ONLY transaction
	txn = new nogdb.Txn(ctx,"READ_ONLY");
// Get initial word from 'InitialWords'
	word1 = nogdb.Vertex.get(txn, "InitialWords");
// Get property 'string' from vertex and print to screen
	str_vertex = word1[0].record.value.messaged.toText;
// Get out edge from record
	edge = nogdb.Vertex.getOutEdge(txn,word1[0].recordDescriptor);
// Get destination vertex from edge
	word2 = nogdb.Edge.getDst(txn,edge[0].recordDescriptor);
// Get property 'string' from another vertex and print to screen
	str_another = word2.record.value.messaged.toText;
// Print result
	console.log(str_vertex + str_another);

• Run

$ node hello_world.js

Output : Hello, World.