Getting Started

The best way to use Npgsql is to install its nuget package.

Npgsql aims to be fully ADO.NET-compatible, its API should feel almost identical to other .NET database drivers. Here's a basic code snippet to get you started.

var connString = "Host=myserver;Username=mylogin;Password=mypass;Database=mydatabase";

using (var conn = new NpgsqlConnection(connString))
{
    conn.Open();

    // Insert some data
    using (var cmd = new NpgsqlCommand())
    {
        cmd.Connection = conn;
        cmd.CommandText = "INSERT INTO data (some_field) VALUES (@p)";
        cmd.Parameters.AddWithValue("p", "Hello world");
        cmd.ExecuteNonQuery();
    }

    // Retrieve all rows
    using (var cmd = new NpgsqlCommand("SELECT some_field FROM data", conn))
    using (var reader = cmd.ExecuteReader())
        while (reader.Read())
            Console.WriteLine(reader.GetString(0));
}

You can find more info about the ADO.NET API in the MSDN docs or in many tutorials on the Internet.

DbProviderFactory

The example above involves some Npgsql-specific types (NpgsqlConnection, NpgsqlCommand...), which makes your application Npgsql-specific. If your code needs to be database-portable, you should use the ADO.NET DbProviderFactory API instead (see this tutorial). In a nutshell, you register Npgsql's provider factory in your application's App.config (or machines.config) file, and then obtain it in your code without referencing any Npgsql-specific types. You can then use the factory to create a DbConnection (which NpgsqlConnection extends), and from there a DbCommand and so on.

To do this, add the following to your App.config:

<system.data>
  <DbProviderFactories>
    <add name="Npgsql Data Provider" invariant="Npgsql" description=".Net Data Provider for PostgreSQL" type="Npgsql.NpgsqlFactory, Npgsql, Culture=neutral, PublicKeyToken=5d8b90d52f46fda7"/>
  </DbProviderFactories>
</system.data>

GAC Installation

In some cases you'll want to install Npgsql into your Global Assembly Cache (GAC). This is usually the case when you're using a generic database program that can work with any ADO.NET provider but doesn't come with Npgsql or reference it directly. For these cases, you can download the Npgsql Windows installer from our Github releases page: it will install Npgsql (and optionally the Entity Framework providers) into your GAC and add Npgsql's DbProviderFactory into your machine.config file. This is not the general recommended method of using Npgsql - always install via Nuget if possible. In addition to Npgsql.dll, this will also install System.Threading.Tasks.Extensions.dll into the GAC.

Visual Studio Integration

If you'd like to have Visual Studio Design-Time support, give our VSIX extension a try.

Unstable Packages

The Npgsql build server publishes CI nuget packages for every build. If a bug affecting you was fixed but there hasn't yet been a patch release, you can get a CI nuget at our stable MyGet feed. These packages are generally stable and safe to use (although it's better to wait for a release).

We also publish CI packages for the next minor/major version at our unstable MyGet feed. These are definitely unstable and should be used with care.