# SqlConnection

*noun*

say it: **“ESS-kyoo-EL kuh-NEK-shun”** **/ˌɛs kjuː ˈɛl kəˈnɛkʃən/**

The ADO.NET class that opens a connection from a C# program to a SQL Server database.

## What is **SqlConnection** in C#?

**SqlConnection** — The ADO.NET object that opens a connection to one SQL Server database, from a connection string. Create it with `using`, so the connection is closed for you when you're done.

```csharp
using Microsoft.Data.SqlClient;

using SqlConnection connection = new(
    "Server=localhost;Database=Northwind;Integrated Security=True;TrustServerCertificate=True");
connection.Open();
Console.WriteLine(connection.State); // Open
```

## In a sentence

- “I wrapped the **SqlConnection** in a using statement so it closes when the method ends.”

Level: Journeyman · [More C# terms at this level](https://www.ask-codey.com/glossary?category=c-sharp&level=3)

Updated: October 28, 2026

Source: https://www.ask-codey.com/glossary/sqlconnection