NoSQL Database with SQLite (Custom Implementation)

This project provides a simple NoSQL-style database using SQLite. Similar to MongoDB, data is stored in JSON format, and each entry is assigned a unique _id. The database supports fundamental MongoDB-like operations such as insertOne, find, findOne, and createCollection.

Table of Contents

• Installation
• Usage
  • Database Connection
  • Creating a Collection
  • Inserting Data (insertOne)
  • Querying Data (find and findOne)
  • Closing the Database (close)
• API Functions
  • createCollection
  • insertOne
  • find
  • findOne
  • close
• Testing

Installation

1. Install Node.js
   Ensure you have Node.js installed on your system.

2. Install Dependencies
   Run the following command in your project's root directory:

   npm install

   This will install all required dependencies, including SQLite3 and UUID.

Usage

Database Connection

To establish a connection to the database:

const NoSQLDB = require("oxzof-nosql");
const db = new NoSQLDB();

Once connected, you will see the message: Database connected.

Creating a Collection

To create a new collection:

await db.createCollection("users");

If the collection already exists, it will not be recreated.

Inserting Data (insertOne)

To insert a new document:

await db.insertOne("users", { name: "John", age: 25, gender: "M" });

This operation automatically assigns a unique _id and stores the data in the collection.

Querying Data (find and findOne)

• Retrieve all documents:

const users = await db.find("users");
console.log(users); // Lists all users

• Find a specific document:

const user = await db.findOne("users", { name: "John" });
console.log(user); // Returns the first matching document

find returns an array of all matching documents, while findOne returns only the first match.

Closing the Database (close)

To close the database connection:

db.close();

This function terminates the database connection and stops the application.

API Functions

createCollection(name)

Creates a new collection.

• Parameters:

  • name (String): The name of the collection.

• Example:

  await db.createCollection("users");

insertOne(collection, data)

Inserts a document with a unique _id and stores it in JSON format.

• Parameters:

  • collection (String): The collection name.
  • data (Object): The document to be inserted.

• Example:

  await db.insertOne("users", { name: "John", age: 25, gender: "M" });

• Return Value: { _id, ...data }: Returns the inserted document.

find(collection, filter)

Finds all documents in a collection. Filtering is optional.

• Parameters:

  • collection (String): The collection name.
  • filter (Object): The search criteria.

• Example:

  const users = await db.find("users", { name: "John" });
  console.log(users);

• Return Value: Array: Returns an array of matching documents.

findOne(collection, filter)

Finds the first document that matches the filter criteria.

• Parameters:

  • collection (String): The collection name.
  • filter (Object): The search criteria.

• Example:

  const user = await db.findOne("users", { name: "John" });
  console.log(user);

• Return Value: Object: Returns the first matching document.

close()

Closes the database connection.

• Example:

  db.close();

Testing

Below is a sample index.js file to test the project:

const NoSQLDB = require("oxzof-nosql");
const db = new NoSQLDB();

async function main() {
    console.log(await db.createCollection("users"));

    // Each inserted document will have a unique _id
    console.log(await db.insertOne("users", { name: "John", age: 25, gender: "M" }));
    console.log(await db.insertOne("users", { name: "Mike", age: 30, gender: "M" }));
    console.log(await db.insertOne("users", { name: "Anna", age: 22, gender: "F" }));

    console.log("All users:", await db.find("users"));
    console.log("Find John:", await db.findOne("users", { name: "John" }));

    db.close();
}

main();

About the Project

This project provides a NoSQL-style database architecture on top of SQLite. It is ideal for those who need the flexibility of NoSQL databases like MongoDB while leveraging the simplicity of a file-based SQLite storage system. Each inserted document is assigned a unique _id and is stored in JSON format.