Mini SQL Engine with Query Optimizer

Introduction

SQL is one of the most widely used languages for managing data, but the internal compiler-related steps are often hidden from users. Traditional database systems process complex queries behind the scenes, making it difficult for students to see how lexical scanning and syntax parsing actually evaluate mathematical and relational conditions.

The Mini SQL Engine is designed to bridge theory and practice by parsing, validating, and executing a subset of SQL commands. It functions as a custom compiler pipeline, utilizing Flex for lexical tokenization and Bison for syntax parsing, all seamlessly wrapped in a modern, responsive Python-based Graphical User Interface (GUI) for easy interaction.

Features

• DDL & DML Commands: CREATE TABLE and INSERT INTO with automated .schema and .csv file generation
• Data Retrieval: SELECT queries with specific column projection or SELECT *
• Conditional Filtering: WHERE clauses supporting multiple comparison operators (=, >, <, >=, <=, !=)
• Aggregate Functions: Mathematical summaries including COUNT, SUM, AVG, MIN, and MAX
• Subqueries: Support for single-table nested subqueries
• Modern GUI: Dark-themed desktop application with dynamic tabular data grids

Built With

• Languages: C, Python 3
• Core Tools: Flex, Bison, CustomTkinter
• Compiler & Build System: GCC, Make (mingw32-make)
• Editor: VS Code / CodeBlocks

How to Run

1. Clone the repository: git clone https://github.com/gaziatiqullah/mini-sql-engine.git
2. Navigate to the project folder: cd mini-sql-engine
3. Build the C backend: mingw32-make clean && mingw32-make
4. Launch the GUI: python gui/app.py

Team Members

Name	Student ID	Role
Gazi Atiq Ullah Nabil	242-15-032	Core Engine, File Storage & Integration
Khandakar Tajul Islam	242-15-192	Single-Table Subqueries
Abir Washi	242-15-972	Frontend GUI & Middleware Integration
Sheikh Mahir Faisal	242-15-991	WHERE Clause & Comparison Logic
Shaidur Rahman Shanu	242-15-993	Aggregate Functions

Submitted To

Tamanna Sultana
Lecturer
Department of Computer Science and Engineering
Daffodil International University

Submission Date

August 17, 2026