SQL Database Query Portfolio

This repository contains a collection of SQL labs, progressing from basic queries to advanced server-side logic. The queries were written for a sample database (e.g., coffee sales, points of sale) to solve specific business and analytical problems.

Database Schema

All queries in this project are based on the following relational database schema:

Skills Demonstrated

This portfolio demonstrates a strong understanding of database operations, including:

• Foundational Queries: SELECT, WHERE, COUNT, GROUP BY, ORDER BY, LIKE, and AVG.
• Complex Joins: INNER JOIN and LEFT JOIN across multiple (up to 8) normalized tables.
• Data Filtering: Advanced WHERE clauses, subqueries (WHERE...IN), and date range filtering.
• Data Aggregation: GROUP BY on multiple columns and filtering results with HAVING.
• Database Objects:
  • Creating and using VIEWs to simplify complex queries.
  • Creating STORED PROCEDURES to encapsulate business logic, handle parameters, and raise errors.
  • Implementing TRIGGERS to automatically maintain data integrity or create audit logs.

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Project Structure

The labs are organized by complexity:

• /labo1-basics/
  • Contains foundational SELECT statements, filtering, and aggregation.
• /labo2-advanced-queries/
  • Focuses on complex data retrieval using multi-table JOINs, VIEWs, and subqueries.
• /labo3-server-logic/
  • Demonstrates server-side logic using CREATE PROCEDURE and CREATE TRIGGER.