Names:Hagenimana Aime De dieu

Id:28039

Group:E

SQL Function Exercises – Assignment

Description

This project is a collection of SQL queries solving 50 exercises based on:

• String Functions
• Numeric Functions
• Date/Time Functions
• Conditional Logic

The exercises use a case study with the following tables:

• employees
• departments
• projects
• employee_projects

The goal is to practice and demonstrate SQL functions in a real-world employee-project scenario.

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📁 File

• database_work.sql
  Contains all 50 SQL queries organized by category. Each query is numbered according to the question.

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📂 Query Sections

1️⃣ String Function Exercises (1–15)

• Examples: concatenation, lowercase, substring, email modification, formatting.

2️⃣ Numeric Function Exercises (16–25)

• Examples: rounding, modulus, salary difference, power function, salary categorization.

3️⃣ Date/Time Function Exercises (26–35)

• Examples: current date, hire duration, extract parts of date, ongoing project check.

4️⃣ Conditional Function Exercises (36–50)

• Examples: CASE statements for categorization, COALESCE usage, seniority, increment bands.

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Sample Queries

-- 1. Concatenate first and last name
SELECT CONCAT(first_name, ' ', last_name) AS full_name FROM employees;

-- 18. Calculate project duration in days
SELECT project_id, end_date - start_date AS duration_days FROM projects;

-- 36. Label salaries
SELECT employee_id, salary,
  CASE 
    WHEN salary >= 7000 THEN 'High'
    WHEN salary >= 4000 THEN 'Medium'
    ELSE 'Low'
  END AS salary_label
FROM employees;