How to Connect to PostgreSQL in .NET with C#

Connect using Server Explorer

To connect to your PostgreSQL database in Visual Studio by using the built-in Data Explorer, follow these steps:

1. On the Tools menu, select Connect to Database.

2. In the Add Connection dialog, select PostgreSQL as the data source, and then click OK.

3. Enter your server connection details, and then click OK.

Once connected, you can browse tables, run queries, and manage data directly in Visual Studio.

Connect with EF Core using Entity Developer

If you need to create an EF Core model from your PostgreSQL database, use a visual ORM designer such as Entity Developer.

Entity Developer lets you design and generate EF Core models visually, so you can build the data layer faster and with less manual work. If you do not have Entity Developer installed, close Visual Studio, download Entity Developer, and complete the installation by following the on-screen instructions.

To build your database model, follow the detailed illustrated guide for Entity Developer. When the process finishes, Entity Developer opens the generated model. You can work with the diagram, edit fields and relationships, and generate SQL to apply changes—either as a script or directly to the database.

All steps in this guide use Visual Studio. If you work in VS Code, JetBrains Rider, or a similar IDE, you can run Entity Developer as a standalone application and work with your models just as efficiently.

Use the following example to check a database connection in an EF Core C# Console application when connection settings are stored in the DbContext class.

class Program {
static void Main(string[] args) {
// Create an instance of the DbContext
var context = new DvdRentalContext();

try {
// Attempt to open the connection
  	context.Database.OpenConnection();
  	Console.WriteLine("Connection opened successfully.");

// Check the connection state
if (context.Database.GetDbConnection().State == System.Data.ConnectionState.Open) {
    	Console.WriteLine("Connection is open.");
  	} else {
    	Console.WriteLine("Connection is not open.");
  	}
	} catch (Exception ex) {
  	Console.WriteLine("An error occurred: " + ex.Message);
	} finally {
// Close the connection
  	context.Database.CloseConnection();
	}
  }
}

Connect with EF Core using Scaffold-DbContext

1. First, make sure EF Core tools are available in your environment. Install the CLI tool globally.

dotnet tool install --global dotnet-ef

2. Install the EF Core tools package for your project (Package Manager Console).

Install-Package Microsoft.EntityFrameworkCore.Tools

3. Generate the DbContext and entity classes from your PostgreSQL database. Run the following command in the Package Manager Console (replace the connection values as needed).

Scaffold-DbContext "Server=127.0.0.1;Port=5432;UserId=TestUser;Password=TestPassword;Database=dvdrental;Schema=public;LicenseKey=**********" Devart.Data.PostgreSql.EFCore -OutputDir Models

4. Review the generated DbContext and entity classes and verify that they reflect your database schema.

Video tutorial: How to connect a .NET console application to a PostgreSQL database

Conclusion

This article provides detailed guidance on how to connect .NET applications to a PostgreSQL database by using several approaches. It covers multiple connection options, including SSL/TLS, and shows how to use Entity Framework Core with Scaffold-DbContext.

Devart dotConnect for PostgreSQL can help improve application responsiveness and reduce overhead in common database operations. Start a free trial to evaluate connectivity, performance, and security in your .NET projects.

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