Table of Contents
Warning

T4 templates are obsoleted and replaced with new dotnet tool. Tool documentation could be found here.

Getting started with LINQ To DB with an Existing Database

In this walkthrough, you will build a console application that performs basic data access against a Microsoft SQL Server database using LINQ To DB. You will use existing database to create your model.

Tip

You can view this article's sample on GitHub.

Prerequisites

The following prerequisites are needed to complete this walkthrough:

Tip

Northwind Database script file, which could be executed using Microsoft SQL Server Management Studio

Create new project

  • Open Visual Studio

  • File > New > Project...

  • From the left menu select Templates > Visual C# > Windows Classic Desktop

  • Select the Console App (.NET Framework) project template

  • Ensure you are targeting .NET Framework 4.5.1 or later

  • Give the project a name and click OK

Install LINQ To DB

To use LINQ To DB, install the package for the database provider(s) you want to target. This walkthrough uses SQL Server. For a list of available providers see Database Providers.

  • Tools > NuGet Package Manager > Package Manager Console

  • Run Install-Package linq2db.SqlServer

Generate model from database

Now it's time to generate your model from database.

  • Project > New Folder...

  • Enter DataModels as the name and click OK

  • DataModels > Add Item... and select Text Template

  • Enter Northwind.tt as the name and click OK

  • Copy the content from the file Project > LinqToDB.Templates\CopyMe.SqlServer.tt.txt

  • Modify host, database name and credentials for your SQL Server in LoadSqlServerMetadata function call

  • Save Northwind.tt - it should invoke model generation

Tip

There are many ways to customize generation process. Follow this link for details.

Use your model

You can now use your model to perform data access.

  • Open App.config
  • Replace the contents of the file with the following XML (correct connection string based on your server location and credentials)
<?xml version="1.0" encoding="utf-8"?>

<configuration>
  <connectionStrings>
    <add name="MyDatabase" providerName="System.Data.SqlClient"
         connectionString="Data Source=.;Database=Northwind;Integrated Security=SSPI;" />
  </connectionStrings>
</configuration>

  • Open Program.cs

  • Replace the contents of the file with the following code

using System;
using System.Linq;

namespace GetStarted
{
	class Program
	{
		static void Main(string[] args)
		{
			using (var db = new DataModel.NorthwindDB())
			{
				var q =
					from c in db.Customers
					select c;

				foreach (var c in q)
					Console.WriteLine(c.ContactName);
			}
		}
	}
}
  • Debug > Start Without Debugging

You will see list of Contact names.

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