ADO.NET

Overview

ADO.NET provides a rich set of components for building data-driven applications on the Windows platform. It enables you to connect to relational databases, execute commands, and retrieve results efficiently.

Key Concepts

• Connection – Manages the link to a data source.
• Command – Executes SQL statements and stored procedures.
• DataReader – Provides fast, forward‑only access to query results.
• DataAdapter – Bridges the gap between DataSets and the database.
• Transactions – Ensure atomic operations.

Getting Started

Install the System.Data.SqlClient NuGet package or use the built‑in library in .NET 6+.

dotnet add package System.Data.SqlClient

Sample code:

using System.Data.SqlClient;

string cs = "Server=.;Database=AdventureWorks;Trusted_Connection=True;";
using var conn = new SqlConnection(cs);
await conn.OpenAsync();
using var cmd = new SqlCommand("SELECT TOP 10 * FROM Production.Product", conn);
using var reader = await cmd.ExecuteReaderAsync();
while (await reader.ReadAsync())
{
    Console.WriteLine($"{reader["ProductID"]}: {reader["Name"]}");
}

Best Practices

• Always use using statements or await using for connections and commands.
• Prefer async APIs for scalability.
• Parameterize queries to prevent SQL injection.
• Leverage connection pooling (default behavior).
• Dispose of SqlDataReader promptly to free resources.

Resources

Official ADO.NET Documentation

GitHub – .NET SqlClient