Data Access Tasks in .NET

Core Technologies and Libraries

.NET offers several foundational technologies for data access:

• ADO.NET: The fundamental data access technology in .NET. It provides a collection of classes that expose data manipulation application services, enabling .NET applications to connect to data sources, retrieve data, and store changes.
• Entity Framework Core (EF Core): A modern, cross-platform, and extensible object-relational mapper (ORM) for .NET. EF Core allows developers to work with databases using .NET objects, abstracting away much of the underlying SQL.
• LINQ to SQL: A component of .NET that provides a run-time infrastructure for translating SQL commands into .NET objects.
• Dependency Injection: Essential for managing data access contexts and repositories in modern .NET applications.

Common Data Access Scenarios

Connecting to Databases

Learn how to establish connections to various database systems, including SQL Server, PostgreSQL, MySQL, SQLite, and more. This involves using connection strings and the appropriate ADO.NET providers or EF Core database providers.

// Example using ADO.NET with SqlConnection
using System.Data.SqlClient;

string connectionString = "Server=myServerAddress;Database=myDataBase;User Id=myUsername;Password=myPassword;";
using (SqlConnection connection = new SqlConnection(connectionString))
{
    connection.Open();
    // Perform database operations
}

Performing CRUD Operations

Understand how to perform Create, Read, Update, and Delete (CRUD) operations on your data. This includes writing SQL queries, using stored procedures, or leveraging ORM features.

Reading Data

Retrieve data from your database. This can be done by executing queries and populating data readers or collections of objects.

Inserting Data

Add new records to your database tables.

Updating Data

Modify existing records in your database.

Deleting Data

Remove records from your database.

Working with Data Models and Schemas

Define your data structures using C# classes and map them to database tables. EF Core's Code-First and Database-First approaches are common patterns.

Handling Transactions

Ensure data integrity by implementing transactions to group multiple operations into an atomic unit.

Asynchronous Data Operations

Improve application responsiveness by performing data access operations asynchronously using async and await keywords.

// Example using EF Core with async operations
var products = await _context.Products
                             .Where(p => p.Price > 50)
                             .ToListAsync();

Advanced Topics

• Data Binding: Connect your data to UI elements in WPF, Windows Forms, or Blazor applications.
• Data Caching: Improve performance by implementing caching strategies for frequently accessed data.
• Data Security: Learn best practices for preventing SQL injection and securing sensitive data.
• ORM Performance Tuning: Optimize EF Core or LINQ to SQL queries for better performance.
• Working with NoSQL Databases: Explore options for connecting to document databases (e.g., MongoDB) or key-value stores.

Getting Started with EF Core

EF Core is the recommended data access technology for most new .NET applications. Follow these steps to get started:

1. Install the necessary EF Core NuGet packages (e.g., Microsoft.EntityFrameworkCore.SqlServer).
2. Define your entity classes representing your data.
3. Create a DbContext class that derives from DbContext.
4. Configure your database connection and mappings in the DbContext.
5. Use the DbContext to query and manipulate data.