SqlIsolationLevelsSimulator

Interactive simulator for testing and visualizing SQL Server isolation level behaviors under concurrent transactions.

🚀 Features

• Simulates concurrent database transactions
• Demonstrates:
  • Dirty Reads
  • Non-repeatable Reads
  • Phantom Reads
  • Deadlocks
• Visualizes the impact of different isolation levels
• Calculates execution time and logs deadlock status

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🔐 Supported Isolation Levels

• Read Uncommitted
• Read Committed
• Repeatable Read
• Serializable

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🗃️ Required Database

This project uses the AdventureWorks2022 sample database to simulate real-world concurrent transactions.

💡 Please download and restore the .bak file in your SQL Server instance before running the simulation.

📥 Download AdventureWorks2022.bak
(Official link from Microsoft SQL Server Samples)

🔄 Restore in SQL Server:

1. Open SQL Server Management Studio (SSMS)
2. Right-click Databases → Restore Database
3. Select the .bak file and restore it as AdventureWorks2022

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🛠️ Technologies Used

• C# (.NET Framework) – UI and transaction simulation logic
• SQL Server – For executing concurrent transactions
• ADO.NET – Database access and command execution
• Windows Forms – User interface
• Multithreading – Simulating parallel operations

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▶️ Getting Started

🧱 Prerequisites

• Visual Studio 2019 or newer
• SQL Server (Express or LocalDB)
• AdventureWorks2022 sample database

⚙️ Setup

1. Clone the repository:

git clone https://github.com/your-username/SqlIsolationLevelsSimulator.git

2. Open SqlIsolationLevelsSimulator.sln in Visual Studio

3. Make sure SQL Server is running and the AdventureWorks2022 database is restored

4. Update App.config if needed:

<connectionStrings>
  <add name="DefaultConnection"
       connectionString="Data Source=localhost;Initial Catalog=AdventureWorks2022;Integrated Security=True" />
</connectionStrings>

5. Run the app with F5

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📊 Example Output

• Isolation Level: Repeatable Read
• Transaction A: Update operation
• Transaction B: Select → Delay → Select again
• ❌ Deadlock: No
• ⏱ Execution Time: 426 ms

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👤 Author

Esma Şen

• 📧 esmaasen5734@gmail.com
• 🐙 GitHub