Rudimentary Database Engine

(DavisBase: Rio de Janeiro) ~ Using Custom Parsed subset of SQL

(1) Environment

• Create a virtual environment with Python 3.9.7+ within a clone of this repo

  git clone https://github.com/0xrutvij/rioDatabaseEngine.git
  
  cd rioDatabaseEngine
  
  # if using virtualenv
  virtualenv venv
  
  # else
  python3 -m venv venv
  
  # then source it (*nix OSes)
  source venv/bin/activate
  
  # install all dependencies
  pip install -r requirements.txt 

(2) Launching the Application

• Launching the SQL REPL

  python3 src/main_loop.py

  The output will be something like this!

  -------------------------------------------
  Welcome to RioDBLite
  RioDBLite Version 0.1
  ©2021 Rio DB Group
  
  Type "help;" to display supported commands.
  -------------------------------------------
  
  
  riodb>

(3) How to Start

• run init db command only the first to initialize the database and create database files, it will create a file named rio.db in the current directory, and supports one database instance per directory.

• Look at the commands supported and sample commands for next steps.

  riodb> init db;

• Subsequent launches should read all tables present in the rio.db file.

• The immediately previous version is backed up at all times to rio.db.bkp, to restore from backup, rename the bkp file to rio.db before next launch and remove any other files of the same name.

(4) Commands Supported (w/ Sample Commands)

• clear: Clear previous input data clear;

• create: create a new table in the database

  CREATE TABLE DOGS 
  (
      TagID int PRIMARY KEY, 
      Name text, Weight float, 
      Age int
  );

• insert: Insert data into a particular table

  INSERT INTO TABLE
  (TagID, Name, Weight, Age) 
  DOGS 
  VALUES (933, "Rover", 20.6, 4);

• select: Query data from the database

  SELECT * FROM DOGS;

• update: Update data in the tables

  UPDATE DOGS SET Age=8 WHERE Name=“Rover”;

• delete: Delete data from a table

  DELETE FROM TABLE DOGS WHERE Name=“Rover”;

• drop: Delete table from database

  DROP TABLE dogs;

• exit: Exit davisbase RioDB exit;