siamdb

---

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

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npm install siamdb

Usage

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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: "[e-mail]", 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

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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.