SQL CHEAT SHEET - Save This!
Most Asked SQL in Tech Interviews!

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SQL is tested in 90% of tech interviews!
TCS, Infosys, Amazon, Flipkart, Data Analyst
roles ALL require strong SQL. Master this!

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BASIC QUERIES

SELECT * FROM employees;
-> Get all rows from table

SELECT name, salary FROM employees
WHERE salary > 50000;
-> Filter rows with condition

SELECT * FROM employees
ORDER BY salary DESC LIMIT 5;
-> Top 5 highest paid employees

SELECT DISTINCT department FROM employees;
-> Get unique departments only

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AGGREGATE FUNCTIONS

SELECT COUNT(*) FROM employees;
-> Total number of rows

SELECT AVG(salary) FROM employees;
-> Average salary

SELECT MAX(salary), MIN(salary) FROM employees;
-> Highest and lowest salary

SELECT department, COUNT(*) as emp_count
FROM employees
GROUP BY department
HAVING COUNT(*) > 5;
-> Departments with more than 5 employees

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JOINS - Most Asked in Interviews!

INNER JOIN - Only matching rows in both tables:
SELECT e.name, d.dept_name
FROM employees e
INNER JOIN departments d ON e.dept_id = d.id;

LEFT JOIN - All from left + matching right:
SELECT e.name, d.dept_name
FROM employees e
LEFT JOIN departments d ON e.dept_id = d.id;

SELF JOIN - Table joined with itself:
SELECT e1.name, e2.name AS manager
FROM employees e1
JOIN employees e2 ON e1.manager_id = e2.id;

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SUBQUERIES - Asked in Advanced Rounds!

Employees earning more than average:
SELECT name FROM employees
WHERE salary > (SELECT AVG(salary) FROM employees);

2nd highest salary (Classic Question!):
SELECT MAX(salary) FROM employees
WHERE salary < (SELECT MAX(salary) FROM employees);

Nth highest salary using LIMIT:
SELECT salary FROM employees
ORDER BY salary DESC LIMIT 1 OFFSET N-1;

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WINDOW FUNCTIONS - Modern SQL!

Rank employees by salary:
SELECT name, salary,
RANK() OVER (ORDER BY salary DESC) as rnk
FROM employees;

Row number within each department:
SELECT name, department,
ROW_NUMBER() OVER
(PARTITION BY department ORDER BY salary DESC)
FROM employees;

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TOP 5 SQL INTERVIEW QUESTIONS:

1. Find duplicate records in a table
2. Find employees with no manager (NULL)
3. Find departments with zero employees
4. Find Nth highest salary
5. Difference between WHERE and HAVING?

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PRACTICE FREE ON:
SQLZoo -> sqlzoo.net
HackerRank -> hackerrank.com/domains/sql
LeetCode -> leetcode.com/problemset/database

====================================
Save this before your next interview!
Get FREE projects with database code:
https://t.me/Projectwithsourcecodes

Share with your placement batch!

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HOSTEL MANAGEMENT SYSTEM - PHP & MySQL
Final Year Project with Full Source Code!

Role-based web app for colleges to manage
hostel registration, room allocation, complaints
and messaging. Perfect for BCA/MCA/BTech!

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#BTech2026 #MCA2026 #BCA2026
#ProjectWithSourceCodes #StudentsOfIndia

HOSTEL MANAGEMENT SYSTEM
PHP + MySQL | Final Year Project

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A role-based web application for colleges to manage hostel
registration, room allocation, complaint handling and internal
communication between students, managers and admins.

KEY FEATURES:
- User registration & role-based login
- Student hostel application workflow
- Room allocation & vacancy management
- Complaint submission & status tracking
- Internal messaging (student <-> manager)
- Full admin control panel

USER ROLES:
- Admin: manages hostels, rooms, users, applications, complaints
- Manager: reviews applications, allocates rooms, handles complaints
- Student: applies for hostel, tracks room, raises complaints

TECH STACK:
- PHP (procedural, MySQLi)
- MySQL database
- HTML, CSS, JavaScript
- Runs on XAMPP / WAMP / LAMP

WHAT YOU GET:
- Complete source code
- Documentation
- Easy installer (install.php) + demo accounts
- Support

====================================
DOWNLOAD / BUY THIS PROJECT:
https://updategadh.com/hostel-management-system-php-and-mysql/

More ready-made projects with source code:
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5 LATEST FINAL YEAR PROJECTS - UPDATEGADH
With Full Source Code + Documentation

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1. Railway Management System - PHP & MySQL
Book, manage & track trains - a classic, impressive DBMS project
https://updategadh.com/railway-management-system-in-php-and-mysql/

2. Agentic RAG AI System - Python
Advanced 2026 AI architecture - build your own agentic RAG system
https://updategadh.com/agentic-rag-ai-system-using-python/

3. AI Online Examination System with Face Detection - PHP & MySQL
Secure online exams with AI proctoring & face detection
https://updategadh.com/online-examination-system-with-face-detection/

4. Real-Time Medical Queue & Appointment System - Django
MediQueue - live patient queue & appointment booking
https://updategadh.com/appointment-system-with-django/

5. Online Examination System - PHP
Complete exam portal for BCA/MCA/B.Tech/M.Tech with source code
https://updategadh.com/online-examination-system-in-php-with-source-code/

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Each project includes:
- Complete source code
- Documentation
- Setup guide & support

====================================
More ready-made projects with source code:
https://t.me/Projectwithsourcecodes

Share with your final-year batch!

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#Django #AI #RAG #DBMS #WebDevelopment #MiniProject
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#ProjectWithSourceCodes #StudentsOfIndia

🛂 VISITOR MANAGEMENT SYSTEM — PHP Project

A lightweight web app for tracking who's coming in and out of your organization — built for security desks and front offices. Here's what's inside 👇

🛠️ ADMIN SECTION
• Employee & department management
• View + filter visitor logs by date
• Generate visitor activity reports
• Manage guard/receptionist user accounts

👮 GUARD (USER) SECTION
• Quick visitor check-in & check-out
• Fast, simple data entry — no clutter

✅ WHY IT'S USEFUL
• Clean, intuitive interface for both admin & guard
• All records organized — employees, departments, visitors
• Role-based access keeps data secure
• Reports make security analysis & planning easier

⚙️ STACK
PHP · MySQL · CSS · Runs on XAMPP

🎓 GOOD FOR
Front-desk security systems, college/final-year projects, or anyone wanting a simple real-world example of role-based (admin vs guard) access control.

🔥 50% OFF right now on the source code!
🛒 Grab it here: https://store.updategadh.com/product/visitor-management-system-in-php/

🔗 Full write-up: https://updategadh.com/visitor-management-system-in-php/

💬 Would your office benefit from something like this? Let us know 👇

#PHPProject #VisitorManagementSystem #WebDevelopment #FinalYearProject #MySQL

🏍️ ONLINE BIKE RENTAL MANAGEMENT SYSTEM — PHP Project

A complete web platform for renting bikes online — bike listings, user accounts, rentals & payments, all in one system. Here's what's inside 👇

🛠️ ADMIN SECTION
• Secure admin login
• Add, update & remove bike listings
• View & manage registered users
• Track & manage bike rentals
• Monitor payment records

🚴 USER SECTION
• Registration & login
• Profile management
• Browse available bikes
• Rent bikes in a few clicks
• View rental history & transactions
• Make payments & track payment status

⚙️ STACK
PHP · MySQL · Bootstrap · HTML/CSS/JS · AJAX/jQuery · Runs on XAMPP/WAMP/LAMP

🎓 GOOD FOR
BCA, MCA, B.Tech CS/IT students & developers who want a real example of user management, rentals, and payment tracking in a database-driven web app — great as an academic or portfolio project.

📦 What you get: Source Code + Database + Project Report + PPT + Viva Questions + Setup Guide

🛒 Grab it here: https://store.updategadh.com/product/bike-rental-management-system/
🔗 Full write-up: https://updategadh.com/bike-rental-management-system/

💬 Ever rented a bike online? Would you build something like this? 👇

#PHPProject #BikeRentalSystem #WebDevelopment #FinalYearProject #MySQL

🚆 Railway Management System in PHP & MySQL

Looking for a Railway Management System project in PHP and MySQL? This complete project is useful for students and developers who want to understand railway reservation and management functionality.

✨ Features:
✅ Train Management
✅ Ticket Booking & Reservation
✅ Passenger Management
✅ Train Schedule Management
✅ User/Admin Login
✅ PHP & MySQL Database
✅ Easy-to-understand project structure

👉 Read the Complete Project:
Railway Management System in PHP & MySQL

#PHP #MySQL #RailwayManagementSystem #PHPProject #MySQLProject #StudentProject #WebDevelopment

🛒 Flipkart Clone using PHP & MySQL! 🚀

A complete E-Commerce Website Project with product management, shopping cart, orders, user login & more. 💻🔥

🛍️ Buy Project: https://store.updategadh.com/product/flipkart-clone/
🔗 Project Details: https://updategadh.com/flipkart-clone/

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🚀 Advance Employee Management System Using PHP & MySQL

A complete HR & Employee Management System built with PHP and MySQL! 💻

🔥 Key Features:
✅ Employee & Department Management
✅ Face Recognition Attendance
✅ Attendance & Leave Management
✅ Payroll Management
✅ Task Management
✅ Notifications & Announcements
✅ Reports & Dashboard Analytics
✅ OpenAI AI Assistant 🤖
✅ AI Attendance Insights
✅ Employee Self-Service Panel

🛠 Tech Stack: PHP, MySQL, Bootstrap 5, JavaScript, Chart.js, face-api.js, TensorFlow.js & OpenAI API.

📚 Project Details & Features:
Read Full Project Details

🛒 Get Complete Source Code:
Buy Project / Get Source Code

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Online Grocery Store in PHP and MySQL

Build a complete Online Grocery Store using PHP and MySQL with a responsive and user-friendly interface.

Key Features:
- User Registration and Login
- Product Categories and Search
- Product Browsing
- Shopping Cart Management
- Checkout and Order Placement
- Cash on Delivery, UPI and Card Payment Options
- Order History and Order Status
- User Profile Management
- Customer Feedback
- Admin Dashboard
- Category and Product Management
- Order Management
- Customer Management
- Feedback Management
- Role-Based Access Control

Technology Used:
PHP, MySQL, HTML, CSS, JavaScript

Project Details:
https://updategadh.com/online-grocery-store-in-php-and-mysql/


#PHP #MySQL #PHPProject #OnlineGroceryStore #WebDevelopment #CollegeProject #SourceCode

Scholarship Management System using PHP and MySQL

A complete web-based project designed to manage scholarship applications through separate Student, Signatory, and Admin dashboards.

Key Features:
- Student Registration and Login
- Signatory Registration and Login
- Admin Dashboard
- Scholarship Application
- Document Upload
- Email Verification using PHPMailer
- Signatory Application Validation
- Admin User Validation
- Accept or Reject Applications
- Application Status and History
- PHP and MySQL Database

Technology Used:
PHP, MySQL, HTML5, CSS3, JavaScript, PHPMailer

Project Details & Source Code:
https://updategadh.com/scholarship-management-system-using-php-and-mysql/


#PHP #MySQL #PHPProject #ScholarshipManagementSystem #CollegeProject #WebDevelopment #StudentProject

Traffic Fine Management System in PHP with MySQL

A complete web-based project designed to manage traffic violations, fines, officers, drivers, payments, receipts, and fine records through a centralized system.

Key Features:
- Admin, Officer, Department and Driver modules
- Traffic Fine Issuing System
- Fine Search and History
- Online Payment UI
- Fine Receipt Generation
- PDF/CSV Report Export
- Officer Management
- Forgot Password
- Support System
- Responsive Interface
- MySQL Database Integration

Technology: PHP, MySQL, HTML, CSS, JavaScript, Bootstrap

Project Details:
https://updategadh.com/traffic-fine-management-system-in-php-with-mysql/

#PHP #MySQL #PHPProject #TrafficFineManagementSystem #CollegeProject #FinalYearProject #WebDevelopment #SourceCode #StudentProject #UPDATEGADH

Online FIR Portal Using PHP and MySQL

Build an advanced Online FIR Portal designed to digitize the FIR filing and police case management process.

Key Features:
- Online FIR Registration
- Complainant Registration & Login
- Multiple FIR Submission
- FIR Case Tracking
- Role-Based Dashboards
- HQ / Admin Dashboard
- Police Station Management
- Police In-Charge Management
- Police Officer Management
- Case Assignment System
- Investigation Updates
- Case Status Management
- Case Timeline & History
- Notifications
- Reports & Analytics
- Dashboard Graphs & Statistics
- Charge-sheet Management
- Supporting Document Upload
- Activity & Audit Logs
- Search, Filter & Pagination
- Secure Authentication & Authorization
- Responsive Professional UI

User Roles:
- Complainant
- HQ / Admin
- Police In-Charge
- Police Officer

Technology:
PHP + MySQL

Suitable for:
- BCA / MCA Students
- Final Year Projects
- College Projects
- PHP & MySQL Projects
- Advanced Web Development Projects

Full Project & Documentation:
https://updategadh.com/online-fir-portal-using-php-and-mysql/

More Projects:
https://updategadh.com/

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