Query Lite SQL

A simple SQL query engine for JSON data with a web interface. This application allows you to run SQL-like queries against flat JSON arrays of objects.

Features

• Parse and execute SQL queries on JSON data
• Web interface for submitting queries and viewing results
• Query history stored in SQLite database
• Support for SELECT, WHERE, and LIMIT clauses

Supported SQL Syntax

• SELECT (comma separated list of columns or *)
• FROM (required but not actually used)
• WHERE (conditions with =, !=, <, >, AND, OR, parentheses)
• LIMIT (integer)

Example queries:

SELECT state FROM table WHERE pop > 10000000 AND state != 'California';
SELECT * FROM table WHERE pop > 20000000 OR (pop > 10000000 AND region = 'Midwest');
SELECT * FROM table WHERE pop_male > pop_female;

Requirements

• GHC (Glasgow Haskell Compiler)
• Cabal

Building the Project

To build the project, run:

cabal build

Running the Application

Run the application with a JSON file as the argument:

cabal run query-lite-sql-exe -- sample.json

Then, open your browser and navigate to:

http://localhost:3000/

Project Structure

• src/ - Source code for the Haskell application
  • QueryLiteSQL/Parser/SQL.hs - SQL parser
  • QueryLiteSQL/Parser/Executor.hs - Query execution engine
  • QueryLiteSQL/Database/Schema.hs - Database schema for query history
  • QueryLiteSQL/Web/Routes.hs - Web routes for the API
  • QueryLiteSQL/Types/Env.hs - Environment configuration
• app/ - Main application entry point
• frontend/ - Web interface
• sample.json - Example JSON data file

Technical Details

• Backend: Haskell with Scotty web framework
• Frontend: HTML, CSS, JavaScript
• Database: SQLite for storing query history
• Libraries:
  • aeson (JSON parsing)
  • attoparsec (SQL parsing)
  • scotty (web framework)
  • sqlite-simple (database access)