Json Database Management

JsonDatabase is a lightweight JSON database management system written in Python and nodejs. It treats json files as database files. It provides a simple way to create, read, update, and delete JSON databases. It also helps to visualise data pandas (python) or pandas-js for node-js

Features

• Create a new JSON database file.
• Read raw and parsed JSON data from the database file.
• Insert new data into the database.
• Delete the entire database or specific keys.
• Update existing data.
• Show database content in a tabular format using Pandas (optional).

For Python:

Installation

Ensure you have Python installed. If you plan to use the show method with Pandas, install Pandas as well:

pip install pandas # optional as it it only needed when to visualise data

Usage

Creating a Database

To create a new JSON database file:

from json_database import JsonDatabase
# OR
from json_database import *


db = JsonDatabase(location=".", name="my_database")
db.create_database()

Reading the Database

To read the raw content of the database:

content = db.read_raw_database() # will return content of json database as a string
print(content)

To read and parse the JSON content:

data = db.read_database() # will return content of json database as a python dictionary
print(data)

Inserting Data

To insert or update data in the database:

db.insert_into(key="user1", data={"name": "Alice", "age": 30})

• If you create a fresh database and run above code, that database is going to look like this

{
"user1":{
  "name": "Alice",
   "age": 30
  },
}

Deleting Data

To delete the entire database file:

db.delete_database()

To delete a specific key from the database:

db.delete_key("user1")

Updating Data

To update existing data:

db.update(key="user1", new_data={"age": 31})

Showing Data in Tabular Form

To display the database content as a Pandas DataFrame:

db.show(toshowORtoreturn="show")  # To print the DataFrame

To return the DataFrame object:

df = db.show(toshowORtoreturn="return")
print(df)

Error Handling

• DatabaseError: Raised for errors related to database operations (e.g., file creation, reading, writing, etc.).
• KeyError: Raised when trying to delete or update a non-existent key.

Example

Here's a complete example demonstrating the it:

from json_database import JsonDatabase

# Create a database
db = JsonDatabase(location=".", name="example_db")
db.create_database()

# Insert data
db.insert_into("user1", {"name": "Alice", "age": 30})

# Read data
data = db.read_database()
print("Data:", data)

# Update data
db.update("user1", {"age": 31})

# Show data
db.show(toshowORtoreturn="show")

#  Delete key
db.delete_key("user1")

# Delete database
db.delete_database()

For Node js:

Here is the documentation for the JsonDatabase class:

JsonDatabase Class

Description

JsonDatabase is a class that provides methods to interact with a JSON-based database stored in a file. The database is created, read, updated, and deleted using the provided methods. Each database is a JSON file stored in a specified directory.

• First you have to install jsonfile dependency by executing the following command.

npm i jsonfile

Constructor

constructor(location = ".", name = "default")

• location: The directory where the database will be stored. Default is the current directory.
• name: The name of the database (without the .json extension). Default is "default".

Methods

create_database

create_database()

Creates the database file and its directory if they do not exist.

Example:

const db = new JsonDatabase();
db.create_database();

Edge Cases:

• If the database file already exists, a warning message will be logged.

read_raw_database

read_raw_database()

Reads the raw content of the database file as a string.

Example:

const rawContent = db.read_raw_database();
console.log(rawContent);

Edge Cases:

• If the database file does not exist, a DatabaseError is thrown.

read_database

read_database()

Reads and parses the content of the database file as a JSON object.

Example:

const data = db.read_database();
console.log(data);

Edge Cases:

• If the database file does not exist, a DatabaseError is thrown.
• If the JSON content is invalid, a DatabaseError is thrown.

insert_into

insert_into(key, data)

Inserts data into the database under the specified key.

• key: The key under which data will be stored.
• data: The data to be stored.

Example:

db.insert_into("user1", { name: "John Doe", age: 30 });

Edge Cases:

• If the key already exists, a warning message will be logged and the existing data will be overwritten.

delete_database

delete_database()

Deletes the database file.

Example:

db.delete_database();

Edge Cases:

• If the database file does not exist, a warning message will be logged.

delete_key

delete_key(key)

Deletes the data associated with the specified key from the database.

• key: The key to be deleted.

Example:

db.delete_key("user1");

Edge Cases:

• If the key does not exist, an error is thrown.

update

update(key, newData)

Updates the data associated with the specified key.

• key: The key to be updated.
• newData: The new data to be merged with the existing data.

Example:

db.update("user1", { age: 31 });

Edge Cases:

• If the key does not exist, an error is thrown.
• If the existing data and new data are both objects, they will be merged. Otherwise, the new data will overwrite the existing data.

write_json

write_json(data)

Writes the given JSON object to the database file.

• data: The JSON object to be written.

Example:

db.write_json({ user1: { name: "John Doe", age: 30 } });

Edge Cases:

• If there is an error writing to the file, a DatabaseError is thrown.

show

async show(toshowORtoreturn = "show")

Displays or returns the database content as a tabular data frame. Requires pandas-js to be installed.

• toshowORtoreturn: If "show", logs the data frame to the console. If "return", returns the data frame.

Example:

db.show();

Edge Cases:

• If pandas-js is not installed, prompts the user to install it. If the user declines, the function exits.

Error Handling

The DatabaseError class is used to handle errors related to database operations.

class DatabaseError extends Error {}

Example Usage

const JsonDatabase = require('./JsonDatabase.js'); //Assuming you JsonDatabase.js file is in the same directory in which nodejs in running

// Initialize the database
const db = new JsonDatabase('.', 'exampleDB');
db.create_database();

// Insert data
db.insert_into('user1', { name: 'John Doe', age: 30 });

// Read data
const data = db.read_database();
console.log(data);

// Update data
db.update('user1', { age: 31 });

// Show data
db.show();

// Delete a key
db.delete_key('user1');

// Delete the database
db.delete_database();

Edge Cases

1. Database File Already Exists: If you attempt to create a database that already exists, a warning will be logged.
2. Invalid JSON Format: If the JSON content is invalid, a DatabaseError will be raised.
3. Key Not Found: Attempting to delete or update a key that does not exist will raise a KeyError.
4. Pandas Not Installed: If Pandas is not installed and you try to use the show method, you will be prompted to install it.

Troubleshooting

• File Permission Issues: Ensure that the directory where the database is being created has the appropriate permissions.
• Invalid JSON: Make sure the data being inserted is valid JSON.

For further assistance or to report issues, please open an issue on the GitHub repository.

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Feel free to customize this it as needed for your specific use case or project requirements!