T-SQL

🛠️ T-SQL Programming & Advanced Database Logic

🚀 Overview

This repository focuses on Transact-SQL (T-SQL), demonstrating the ability to move beyond simple queries into full database programmability. It contains advanced scripts for automating tasks, ensuring data integrity, and optimizing server-side logic in SQL Server.

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🏗️ Technical Proficiencies

1. Procedural Programming & Control Flow

• Logic Flow: Implementation of complex logic using IF...ELSE statements, CASE expressions, and WHILE loops.
• Variable Management: Expert use of Local Variables, Table Variables, and Temporary Tables (#Temp) for efficient data manipulation.
• Error Handling: Robust implementation of TRY...CATCH blocks to manage exceptions and ensure system stability.

2. Programmable Objects (Stored Procedures & Functions)

• Stored Procedures: Building reusable, parameterized scripts for business logic and data security.
• Custom Functions: Development of Scalar-Valued and Table-Valued Functions (TVFs) to simplify complex calculations.
• Dynamic SQL: Crafting flexible queries while maintaining awareness of SQL Injection risks and prevention techniques.

3. Data Integrity & Automation (Triggers)

• Automated Actions: Implementation of AFTER Triggers for auditing and synchronization.
• Custom Logic Overrides: Using INSTEAD OF Triggers to handle complex views and data validation.

4. Advanced Data Retrieval Techniques

• Common Table Expressions (CTE): Writing clean, readable, and recursive queries for hierarchical data.
• Window Functions: Leveraging analytical tools like ROW_NUMBER(), RANK(), and LEAD/LAG for advanced reporting.
• Cursors: Managed use of Cursors for row-by-row processing when set-based logic is insufficient.

5. Transaction Management

• Data Consistency: Mastery of ACID properties using BEGIN TRANSACTION, COMMIT, and ROLLBACK to ensure atomic operations and prevent data corruption.

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🛡️ Security Mindset

• SQL Injection Defense: This module includes specific examples of identifying and preventing SQL injection attacks through proper input sanitization and parameterized queries.

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📂 Folder Structure Reference

• 11 - Stored Procedures: Reusable business logic.
• 08 - Transactions: Ensuring data integrity.
• 21 - CTE: Modern, readable query structures.
• 18/19 - Triggers: Database automation.

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💡 Why T-SQL?

These scripts prove the ability to handle Backend Logic directly at the database level, reducing network latency and improving application performance.