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C#300 Series

Intermediate C#: Collections, LINQ and Database Interactions

Go beyond syntax and learn how to build secure, data-driven applications in C#, with real database access, encryption, and a portfolio-ready final project.

Hours

Intermediate

  Last Updated
June 2025

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This course includes:

  • Access to private discord community
  • lessons, videos, code-alongs, exercises, solutions, projects, and more
  • Unlimited access to all courses, webinars, office hours and resources

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Prerequisites:

This is an intermediate course. You need to have completed the following courses or the equivalent:


Overview

Curriculum

Mentor

FAQs

What we'll cover...

  • Work with C# collections, generics, and iteration for smarter data handling
  • Set up and connect to databases using ADO.NET, Dapper, and Entity Framework Core
  • Use LINQ to efficiently query, filter, and transform data
  • Learn code-first development with SQLite and scaffold databases with EF Core
  • Read, write, and manage files using CSV, JSON, and custom logic
  • Build layered, maintainable apps using N-Tier architecture
  • Secure your applications with hashing, encryption, and environment-based config
  • Apply everything in a real-world Cafe Point-of-Sale system to showcase your skills

Why Learn Collections, LINQ, and Database Interaction?

If you want to move beyond basic programs and start building real applications, these are the skills that unlock everything.

  • Collections let you manage dynamic sets of data: customers, orders, inventory, anything real software handles.
  • LINQ helps you search, sort, filter, and transform that data with clean, expressive code. No more clunky loops.
  • Databases are where real world applications live. Knowing how to connect, query, and manage data makes you capable of building complete, job ready software.

Together, these tools give you the power to:

  • Move from small exercises to full applications
  • Build data driven features like user accounts, reports, and dashboards
  • Impress hiring managers with technical depth and clean code
  • Understand how enterprise grade systems really work

These aren’t just skills, they’re the difference between a beginner and a professional developer.

You’ve got the logic.
Now let’s add data and make it real.

Start learning C# the way pros actually use it.

Curriculum Outline

Module 1: Introduction

  • Get started with the course and download the code samples, exercises, and solutions.
  • Welcome!
  • Getting the Course Materials from Github

Module 2: Introduction to Collections

  • Learn about common C# collection types, generics, and iteration techniques for efficient data management.
  • foreach Loops
  • Legacy Collections
  • Generics in C#
  • Generic Collections
  • Demo: Dice Statistics
  • Exercise: Grocery List Manager
  • Solution: Grocery List Manager
  • Exercise: Restaurant Guest Queue
  • Solution: Restaurant Guest Queue
  • Nullable Types
  • Exercise: Refactoring Airport Locker Rental
  • Solution: Refactoring Airport Locker Rental
  • Quiz: C# Collections

Module 3: Introduction to LINQ

  • Learn Language Integrated Query (LINQ) for powerful data querying and manipulation.
  • Extension Methods
  • Exercise: ToTitleCase()
  • Solution: ToTitleCase()
  • LINQ Method Syntax
  • LINQ Query Syntax
  • Exercise: LINQ Practice Minis
  • Quiz: LINQ

Module 4: Working with Files

  • Explore file system operations, data serialization, and exception handling for robust file management.
  • File and Directory Types
  • Demo: Reading and Writing CSV and JSON Files
  • Handling Exceptions
  • Exercise: Airport Locker Rental File Storage
  • Solution: Airport Locker Rental File Storage
  • Exercise: Hangman
  • Solution: Hangman
  • Quiz: Working with Files

Module 5: Data Protection

  • Implement security best practices including configuration management, encryption, and data protection.
  • Configuration, Secrets, and Environment Variables
  • Secrets, Hashing, and Encryption
  • Demo: Hashing Passwords with Argon2
  • Demo: Encrypting Data with AES
  • Understanding Streams
  • Exercise: Secured Airport Locker Rental
  • Solution: Secured Airport Locker Rental

Module 6: Setting up Database Access

  • Prepare your development environment and understand database security fundamentals.
  • Setup: Docker Desktop and Database Container
  • How Database Security Works
  • Which Data Access Framework to Use?

Module 7: ADO.NET

  • Work with databases using ADO.NET for direct database access and control.
  • Querying Data with ADO.NET
  • DML Queries, Stored Procedures, and Transactions with ADO.NET

Module 8: Dapper .NET

  • Use the lightweight Dapper micro-ORM for efficient database operations.
  • Querying Data with Dapper
  • DML Queries, Stored Procedures, and Transactions with Dapper .NET

Module 9: Entity Framework Basics

  • Entity Framework Core is the most popular package for object-relational mapping and database operations in C#.
  • Querying Data with Entity Framework
  • DML Queries, Stored Procedures, and Transactions with Entity Framework
  • Scaffolding EF Core from a Database

Module 10: SQLite

  • Work with SQLite databases and implement code-first development with Entity Framework.
  • Introducing SQLite
  • Installing SQLite and Tools
  • Code-First in EF Core
  • Exercise: SQLite Airport Locker Rental
  • Solution: SQLite Airport Locker Rental

Module 11: N-Tier Architecture

  • Design reusable layers using multi-tier architectural patterns.
  • N-Tier Architecture
  • Demo: 3 Tier Architecture
  • Exercise: Finish Library Manager
  • Solution: Library Manager

Module 12: Capstone Project

  • Apply all course concepts in a comprehensive point-of-sale application project.
  • Cafe Point of Sale
  • Cafe Point of Sale Solution
  • Next Steps

How We Build Developers

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Written Lessons That Actually Make Sense
 

Our written content explains complex concepts in plain English, with real examples you can quickly apply. You'll understand not just what to do, but why pros make the decisions we do.

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Hands-On Practice That Builds Confidence

Every concept comes with code samples and exercises. You can't learn to play guitar without putting your fingers on the strings and you can't learn to code without writing a lot of code!
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Videos That Show, Don't Just Tell

You'll see how professional developers think, debug, and refactor code. These aren't just lectures, but applied theory. See concepts actually used together!
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Rigorous Capstone Projects That Prove Your Skills

You'll build substantial applications that demonstrate your ability to architect solutions, handle complexity, and deliver professional-quality code.

Join developers who chose...

depth over speed,
understanding over memorization, and 
professional skills over participation certificates.

Frequently asked questions

Who is this course for?

This course is for C# learners who already know basic object-oriented principles and want to take their skills further. If you've covered variables, conditionals, methods, classes, and interfaces, now you're ready for this next step.

You need to have completed the following courses or the equivalent:

What will I be able to build after this course?

You’ll build data-driven applications that use files and relational databases to persist data. Not only that, but you'll be able to make appropriate design decisions about how to structure applications in professionally extensible and maintainable ways.

This course sets the foundation for the "back-end" of full stack development. You'll create application layers that are easily used by web, mobile, and desktop front end layers.

Does this course include database training?

Check out our SQL for Beginners course to understand SQL and relational databases. This course shows you how to use C# collections, LINQ queries, and data frameworks like ADO.NET, Dapper, and Entity Framework Core to connect your applications to real SQL databases.

You’ll learn about configuration, queries, transactions, and schema design using multiple approaches, as well as the wisdom of how to pick the right approach for the situation.

Do I need to know SQL to take this course?

You will need a basic familiarity with SQL. If you’ve never touched SQL before, check out our SQL for Beginners course alongside this one.

What about security? Will I learn best practices?

Absolutely. You'll learn how to handle secrets, hash passwords, encrypt data, and safely manage configurations. Don't be that person that gets made fun of on social media for pushing their credentials and API keys into source control!

Is this included in the Skill Foundry membership?

Yes! This course is fully included in your membership along with access to the C# beginner track, ASP.NET Core, Docker, Python, career preparation, and more.

 How is this different from other C# courses?

We don’t stop at language features, we teach you how to apply them. You’ll work with files, databases, and encryption in the same way professional developers do. It’s not just about writing code, it’s about building real software!

About the Author

Eric Wise

Software Architect | Mentor | Entrepreneur
Eric isn't just another online instructor, he's a veteran software architect, multi-time tech entrepreneur, and someone who's been in every corner of the industry from tech start ups, big corporations, and freelancing.
But what makes Eric truly special is his legendary ability to explain complex concepts in ways that actually stick.

Forge your Future. Learn to Code.

You can’t fast forward time, but you can stop wasting it.

Join now and start making real progress.

Start today.

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Monthly Plan

$75/month

  • Full access to all courses and learning paths
  • Learn at your own pace. No deadlines or pressure
  •  Regular content updates and new project releases
  • Access to our supportive Discord community
  • Help from the Skill Foundry team when you need it

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Annual Plan

$600/year

  • All monthly plan benefits
  • Access 24/7 to all courses and updates