SQL Query Portfolio

Overview

This repository contains structured SQL query development across relational database environments.
It demonstrates practical relational database skills applicable to analytics, reporting, and IT systems environments.

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Core Capabilities Demonstrated

• Data retrieval and filtering using SELECT and WHERE
• Multi-table joins (INNER, LEFT)
• Subqueries and nested query logic
• Aggregation using GROUP BY and HAVING
• Windowing fundamentals
• Relational schema navigation

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Database Environments

• Northwind sample database
• Multi-table relational schemas
• Structured transactional datasets

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Query Categories

1. Fundamentals

Basic query structure, filtering, ordering, and column selection.

2. Aggregation & Grouping

Summaries, counts, totals, averages, grouped reporting logic.

3. Joins & Relational Logic

Multi-table relationships and data combination techniques.

4. Subqueries & Nested Logic

Correlated subqueries and layered data retrieval patterns.

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Repository Structure

/01_fundamentals
/02_aggregation
/03_joins_and_subqueries
/practice_exercises

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Purpose

This repository reflects foundational SQL proficiency in relational database environments and supports roles involving:

• Data analysis
• Reporting
• Database querying
• IT systems support
• Business intelligence workflows

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Notes

All datasets used are sample or publicly available databases for educational and technical demonstration purposes.