Serverside In-App Memory DB

Siam DB is a simple, lightweight in-app memory database for Node.js that provides support for multiple collections of documents. It's designed to be easy to use and to provide a basic set of features for storing and retrieving data, without requiring a lot of configuration or setup.

IMPORTANT: Siam DB does not currently include any persistence mechanism to store data beyond the lifecycle of the application. Therefore, when the application is restarted, all the data in the database will be lost.

Key Features

• Ideal for quickly storing and retrieving data during the testing and prototyping phase of development, without the need for a full database.
• Efficient caching for frequently accessed data in memory for quick access.
• Suitable for storing chat messages in a real-time application, where the persistence of the message history is trivial.

Installation

npm install siamdb

Usage

Create database

You can import the createDatabase function from the package:

import { createDatabase } from "siamdb"
// or
const { createDatabase } = require("siamdb")

Then, create a new instance of the database by calling createDatabase and passing in an options object and a schema object:

const options = {
  generateIds: "autoinc"
}

const schema = {
  users: {
    name: "string",
    email: "string",
    age: "number",
    active: "boolean",
    children: "object"
  },
  posts: {
    title: "string",
    content: "string",
    authorId: "string"
  }
}

const database = createDatabase(options, schema)

Or you may omit options and schema entirely, opting for uuids for ids, and no limitations to the collections you can create and key value types you can use within:

const database = createDatabase()

Once you have a SiamDatabase instance, you can access the collections by calling the collection method:

const users = database.collection("users")
const posts = database.collection("posts")

Each collection has methods for finding, creating, updating, and deleting documents:

// Create a new document
const userId = users.create({ name: "John", email: "[email protected]", age: 25 }) 

// Find an array of documents
const activeUser = users.find({ name: "John" })

// Update documents that match a query
users.update({ id: userId }, { age: 26 })

// Delete documents that match a query
users.delete({ id: userId })

Advanced queries

| Operator | Definition | Input Data Type | Description | Example | |-----------|-----------------------------------|-----------------|---------------------------------------------------------|-----------------------------------------------------| | $exists | Does this exist or not | boolean | Check if a field exists in the document | .find({age: { $exists: true }}) | | $gte | Greater than or equal to | number | Check if a field is greater than or equal to a value | .find({age: { $gte: 18 }}) | | $gt | Greater than | number | Check if a field is greater than a value | .find({age: { $gt: 18 }}) | | $lte | Less than or equal to | number | Check if a field is less than or equal to a value | .find({age: { $lte: 24 }}) | | $lt | Less than | number | Check if a field is less than a value | .find({age: { $lt: 24 }}) | | $in | Matches any value in an array | array | Check if a field's value matches any value in an array | .find({favoriteColors: { $in: ["red", "blue"] }}) | | $nin | Matches none of the values in an array. | array | Check if a field's value does not match any value in an array | .find({favoriteColors: { $nin: ["green", "yellow"] }})| | $ne | Not equal to | any | Check if a field's value is not equal to a specified value | .find({status: { $ne: "inactive" }}) | | $or | Logical OR | array | Check if any of the conditions in the array are true | .find({$or: [{ city: "New York" }, { city: "San Francisco" }]}) | | $and | Logical AND | array | Check if all conditions in the array are true | .find({ $and: [{ active: true },{ verified: true }]}) |

The following is an example utilizing all available operators:

db.collection("user").find({
   age: { $gte: 18, $lte: 24 },
   email: { $exists: true },
   status: { $ne: "inactive" },
   score: { $gt: 0, $lt: 100 },
   favoriteColors: { $in: ["red", "blue"], $nin: ["green", "yellow"] },
   $or: [{ city: "New York" }, { city: "San Francisco" }],
   $and: [
     { active: true },
     { verified: true },
     {
       createdAt: {
         $gte: new Date("2023-01-01"),
         $lt: new Date("2023-04-01"),
       },
     },
   ],
 })

Responses

find()

The find() method returns an array of documents

[
  ...,
  {
    id: 1,
    content: { ... }, // the document content
    version: 1
  }
  ...
]

update()

The update() method returns an array of updated documents

[
  ...,
  {
    id: 1,
    content: { ... }, // the updated document content
    version: 2
  }
  ...
]

create()

The create() method returns a string of new document's id

"1"
//or
"3f9b4392-5257-4cb2-9cad-6bb5dad95424"

delete()

The delete() method returns an array of the deleted document ids

["1"]
//or
["3f9b4392-5257-4cb2-9cad-6bb5dad95424"]

Database Parameters

Options

The createDatabase function accepts an optional options object as the first parameter and an optional schema object as the second parameter:

const database = createDatabase(options, schema)

The options object contains:

• generateIds (optional): Specifies how to generate document IDs. Can be set to "autoinc" to generate IDs automatically as integers starting from 1, or "uuid" to generate UUIDs using the crypto.randomUUID method.

Example:

const database = createDatabase({
  generateIds: "autoinc"
}, ...)

Schema

The optional schema object passed to createDatabase should be an object where each key represents a collection name, and each value represents the schema for that collection. The schema for each collection should be an object where each key represents a field name, and each value represents the data type for that field. The supported data types are that of Javascript's typeof:

• string
• number
• boolean
• object
• function

Example:

const database = createDatabase(..., {
  users: {
    name: "string",
    email: "string",
    age: "number",
    active: "boolean",
    children: "object"
  },
  posts: {
    title: "string",
    content: "string",
    authorId: "string"
  })

ToDo:

• Implement some type of ttl on collections and/or documents.