zetabasejs v1.1.75

ZetabaseJS

A NoSQL database for quick deployment

• Get started
  • Installation
  • Hello World
  • Structure
• Operations
  • Write
  • Read
  • Append
  • List
  • Wipe
  • Query   ⭐ Updated 1.1.73
  • Monitor
• Modules
  • ORM

Get started

Installation

npm install --save zetabasejs

Hello World

const Zetabase = require("zetabasejs")

const db = new Zetabase("database.json") //Specify a filename.

db.write('/', 'Hello World !!')
let data = db.read('/')
console.log("Read DB: ", data) // Read DB:  Hello World !!

Structure

A data node contains 2 parts, data & childNodes.

Write operation will update the value in data, which can be retrieved by Read function.

Append operation will update the value in childNodes, which can be retrieved by List function.

Operations

All operations are synchronized.

Write

db.write('/path', data);
let retrieve = db.read('/path');
console.log(retrieve) //The data is retrieved already.

db.write('/path/notExistFolder/subFolder', data); //The missing path will be created automatically.

db.write('/wallet', {balance: 351.5, timestamp: 1565485663}) //Just write the object into db.

Read

let balance = db.read('/wallet') //Retrieve the value in data part.
Output: { balance: 351.5, timestamp: 1565485663 }
// The value will be null if empty.

Append

db.append('/cart', {productCode: '#704FV4', price: 30, timestamp: 1565485663})
db.append('/cart', {productCode: '#604PG4', price: 20.9, timestamp: 1565485703})
db.append('/cart', {productCode: '#204KJ4', price: 70.4, timestamp: 1565485710})
db.append('/cart', {productCode: '#304TI2', price: 3.9, timestamp: 1565485716})

//The objects will be added to the childNodes with an unique key.

List

//List all appended objects.
db.list('/cart', (product, key)=>{
    console.log(`
        Product: ${JSON.stringify(product)}
        Key: ${key}
    `)
})

Product: {"productCode":"#704FV4","price":30,"timestamp":1565485663,"key":"2b0941aab466211b1c0752719c3d693b"}
Key: 2b0941aab466211b1c0752719c3d693b

Product: {"productCode":"#604PG4","price":20.9,"timestamp":1565485703,"key":"0c0381d3010fa7197d1658733cf2002a"}
Key: 0c0381d3010fa7197d1658733cf2002a

...

//Nested list.

let receiptKey = db.append('/receipts', {customerId: '#c001', totalPrice: 53.6, timestamp: 1565485716})

db.append('/receipts/'+receiptKey, {productCode: '#704FV4', price: 30, timestamp: 1565485663})
db.append('/receipts/'+receiptKey, {productCode: '#604PG4', price: 20.9, timestamp: 1565485703})
db.append('/receipts/'+receiptKey, {productCode: '#204KJ4', price: 70.4, timestamp: 1565485710})
db.append('/receipts/'+receiptKey, {productCode: '#304TI2', price: 3.9, timestamp: 1565485716})

db.list('/receipts', (receipt, key, products_dataNode)=>{
    products_dataNode.list(product=>console.log(`
    'Product code:', ${product.productCode},
    'Price:', ${product.price},
    'Timestamp:', ${product.timestamp}
    `))
})

Wipe

//The empty folder will be removed automatically.

db.write('/A/B', 'Content in B')
db.write('/A/B/C/D', 'Content in D')
// In memory
{
    "data": null,
    "childNodes": {
      "A": {
        "id": "A",
        "data": null,
        "childNodes": {
          "B": {
            "id": "B",
            "data": "Content in B",
            "childNodes": {
              "C": {
                "id": "C",
                "data": null,
                "childNodes": {
                  "D": {
                    "id": "D",
                    "data": "Content in D",
                    "childNodes": {}
                  }
                }
              }
            }
          }
        }
      }
    }
}
db.wipe('/A/B/C/D')
// In memory, folder C is removed automatically
{
    "data": null,
    "childNodes": {
      "A": {
        "id": "A",
        "data": null,
        "childNodes": {
          "B": {
            "id": "B",
            "data": "Content in B",
            "childNodes": {}
          }
        }
      }
    }
}

Query

let aliceId = db.append("/Customers", { name: "Alice", gender: "F" })
let katyId = db.append("/Customers", { name: "Katy", gender: "F" })
let bobId = db.append("/Customers", { name: "Bob", gender: "M" })
let tomId = db.append("/Customers", { name: "Tom", gender: "-" })

let waterId = db.append("/Product/drinks", { name: "Water", description: "300ml" })
let breadId = db.append("/Product/foods", { name: "Bread" })

db.append("/Transactions", {
    customerId: aliceId, products: [
        { productCode: waterId, quantity: 10 },
        { productCode: breadId, quantity: 6 },
    ]
})

db.append("/Transactions", {
    customerId: bobId, products: [
        { productCode: breadId, quantity: 40 }
    ]
})

// Query all female/not gender specified customers
let customers = db.query("/Customers/:key/@{name, gender}", {
    gender: val => ['F', '-'].includes(val)
})
// Output
// [ { name: 'Alice', gender: 'F' },
//   { name: 'Katy', gender: 'F' },
//   { name: 'Tom', gender: '-' } ]

// Query all transactions for Alice and Katy
let transactions = db.query("/Transactions/:key/@{}", {
    customerId: val => [aliceId, katyId].includes(val)
})
// Output
// [ { customerId: '6a7b5c84159b2e05837a2c4a3fcf5a6b',
//     products: [ [Object], [Object] ],
//     key: '9d705f589d16f6e69067679f479bab2f' } ]

// Query all transactions that contains water.
transactions = db.query("/Transactions/:key/@{}", {
    products: val => val.filter(v => v.productCode == waterId).length > 0
})
transactions.map(trans => {
    let cust = db.read("/Customers/" + trans.customerId)
    console.log(`Customer:\t${cust.name}`)
    console.log(`Product:\t${JSON.stringify(trans.products, null, 2)}`)
})

// Output
// Customer:       Alice
// Product:        [
//   {
//     "productCode": "17978e7bdb1b9eb1deffa6e37883c34a8DEbA",
//     "quantity": 10
//   },
//   {
//     "productCode": "fd08c2ebcef2c7243017a058ad650f898DEbA",
//     "quantity": 6
//   }
// ]

Monitor

Monitor changes in that level only.

// There are 3 action codes, WRITE, APPEND and WIPE

db.monitor('/Supermarket/status', status=>console.log("Supermarket's status is changed: ", status))
db.monitor('/Supermarket/purchaseOrder', (order, actCode) => {
    if (actCode === "APPEND") {
        console.log(`
        An order is made.\n
        orderId:, ${order.id},
        totalAmount:, ${order.totalAmount}
        `)
    } else if (actCode === "WIPE") {
        console.log(`
        This order is cancelled.\n
        orderId:, ${order.id},
        totalAmount:, ${order.totalAmount}
        `)
    }
})

let orderKey = db.append('/Supermarket/purchaseOrder', { id: '#o001', totalAmount: 100 })

// Output
// An order is made.

// orderId:, #o001,
// totalAmount:, 100

db.wipe('/Supermarket/purchaseOrder/'+orderKey)

// Output
// This order is cancelled.

// orderId:, #o001,
// totalAmount:, 100

db.write('/Supermarket/status', 'Closed');

// Output
// Supermarket's status is changed:  Closed

Modules

ORM

const Zetabase = require("zetabasejs")
const crypto = require('crypto')

// Require the Model class, which contains 3 properties
// __ctime__: creation time
// __mtime__: last modify time
// __key__: entity's key
const { Model } = require("zetabasejs/orm")

// Pass option { orm: true } to Zetabase constructor
// Default is false
const db = new Zetabase('./ormDemo.json', { orm: true })

// 
class Product extends Model {
    constructor(name, productCode, price) {
        super()
        this.name = name;
        this.productCode = productCode;
        this.price = price;
    }

    description() {
      console.log(`Product name: ${this.name}, Product Code: ${this.productCode}, Price: ${this.price}`)
    }
}

db.wipe('/')
for (let i = 0; i < 5; i++) {
    let name = {
        en: crypto.randomBytes(2).toString('hex'),
        zh: crypto.randomBytes(4).toString('hex')
    }
    new Product(name, crypto.randomBytes(8).toString('hex'),
        Math.floor(Math.random() * 100) + 1).put()
}

let options = {
  filters: { price: v => v > 50 }, //Filter
  fields: '{__key__, name, name.zh, productCode, price}', // Select the response value, default is all.
  get: false //Default is true, which return an instance. Set to false to return the object contains the selected fields only.
}

let prods = Product.query(options); //Pass options object as params

// prods 
[
  {
    __key__: '350295370a6b98fb63cc0c8495f00984',
    name: { en: 'b3ca', zh: 'c3700382' },
    'name.zh': 'c3700382',
    productCode: '2bc6fb0714f2585e',
    price: 95
  },
  {
    __key__: 'eba710dc0a6185b6512ba0dfad2d75a3',
    name: { en: '55ab', zh: '206a6a6e' },
    'name.zh': '206a6a6e',
    productCode: '52ac26b1796b657d',
    price: 93
  }
]

let firstProd = prods[0] //The query result is an object.
firstProd.description()

// firstProd
Product {
  __ctime__: 1574498716475000,
  __mtime__: 1574498716475000,
  __key__: '350295370a6b98fb63cc0c8495f00984',
  name: { en: 'b3ca', zh: 'c3700382' },
  productCode: '2bc6fb0714f2585e',
  price: 95
}

//Output Product name: [object Object], Product Code: 8b81f7f2d494d061, Price: 90