CSI Assignment 3 - Celebal Technologies SQL Internship (Week 3)

This repository contains the solutions to Level-C SQL tasks (Task 1 to Task 20) assigned during Week 3 of the Celebal Technologies Summer Internship Program.

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📌 Tasks Covered

Task No.	Description
1	Identify projects with consecutive task end dates and display their start and end dates using grouping logic
2	Find names of students whose best friends got higher salary than them
3	Find all symmetric pairs (X, Y) and (Y, X) from a 2D function table
4	Aggregate stats for each contest by combining submissions and views
5	For each day of the contest, display number of hackers and lowest hacker ID with name
6	Calculate Manhattan distance using min/max LAT_N and LONG_W from a STATION table
7	Print all prime numbers ≤ 1000 in a single line separated by '&'
8	Pivot OCCUPATIONS table to display names under Doctor, Professor, Singer, and Actor columns
9	_Reserved
10	_Reserved
11	_Reserved
12	Display the percentage ratio of cost by Job Family across India and International
13	Compute month-on-month cost-to-revenue ratio of a Business Unit (BU)
14	Show headcount of Sub Bands and percentage (without joins/subqueries)
15	Retrieve top 5 employees by salary (without using ORDER BY)
16	Swap values of two columns in a table without a third variable
17	Create login, user, and assign db_owner permissions
18	Find weighted average cost of employees month-wise by BU
19	Calculate error in average salary due to missing '0' key
20	Copy only new data from source table to target table without indicators

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🛠️ Technologies Used

• SQL Server
• Common Table Expressions (CTEs)
• Window Functions (ROW_NUMBER, RANK, COUNT OVER)
• Aggregate Functions (SUM, AVG, ROUND, CEILING)
• DDL/DML (Table creation, insertion, updates)
• User and permission management in SQL Server

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🧪 Sample Data

Each task includes:

• Table schema (CREATE TABLE)
• Sample data (INSERT INTO)
• SQL queries to solve the problem

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🚀 How to Use

1. Clone the repository
2. Open the .sql file in SQL Server Management Studio or Azure Data Studio
3. Execute task-wise blocks to verify logic and output

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📩 Contact

Aniruddha Sarkar
📧 aniruddhas387@gmail.com
🌐 LinkedIn

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This assignment is part of the Celebal Technologies Summer Internship Program 2025 (Batch 2 - SQL Domain).