Working with PostgreSQL Data in LINQPad

The CData ADO.NET Provider for PostgreSQL enables you to use standard ADO.NET interfaces like LINQ and the Entity Framework to work with PostgreSQL data. This article will demonstrate the process of establishing a connection from LINQPad and executing LINQ queries.

Create the Data Model

After downloading and installing both the provider and LINQPad, create a new class library project within Visual Studio.

See the help documentation for a guide to setting up an EF 6 project to use the provider.

1. Right-click your project and click Add -> New Item -> ADO.NET Entity Data Model. In the resulting dialog, select Code First from database. Click New Connection and specify the connection string options in the resulting wizard.

   To connect to PostgreSQL, set the Server, Port (the default port is 5432), and Database connection properties and set the User and Password you wish to use to authenticate to the server. If the Database property is not specified, the data provider connects to the user's default database.

   SSH Connectivity for PostgreSQL

   You can use SSH (Secure Shell) to authenticate with PostgreSQL, whether the instance is hosted on-premises or in supported cloud environments. SSH authentication ensures that access is encrypted (as compared to direct network connections).

   SSH Connections to PostgreSQL in Password Auth Mode

   To connect to PostgreSQL via SSH in Password Auth mode, set the following connection properties:

   • User: PostgreSQL User name
   • Password: PostgreSQL Password
   • Database: PostgreSQL database name
   • Server: PostgreSQL Server name
   • Port: PostgreSQL port number like 3306
   • UserSSH: "true"
   • SSHAuthMode: "Password"
   • SSHPort: SSH Port number
   • SSHServer: SSH Server name
   • SSHUser: SSH User name
   • SSHPassword: SSH Password

   SSH Connections to PostgreSQL in Public Key Auth Mode

   To connect to PostgreSQL via SSH in Password Auth mode, set the following connection properties:

   • User: PostgreSQL User name
   • Password: PostgreSQL Password
   • Database: PostgreSQL database name
   • Server: PostgreSQL Server name
   • Port: PostgreSQL port number like 3306
   • UserSSH: "true"
   • SSHAuthMode: "Public_Key"
   • SSHPort: SSH Port number
   • SSHServer: SSH Server name
   • SSHUser: SSH User name
   • SSHClientCret: the path for the public key certificate file

   Below is a typical connection string:

   User=postgres;Password=admin;Database=postgres;Server=127.0.0.1;Port=5432;

   👁 The required connection properties in the Entity Data Model Configuration Wizard. (JSON is shown.)
   

2. Select the desired tables and views and click Finish to create the data model.

   👁 The last step of the Entity Data Model Configuration Wizard, where tables are imported into the entity model.
   
3. Build the project. The generated files can be used to create the PostgreSQL connection in LINQPad.

Connect to PostgreSQL Data in LINQPad

After you have obtained the required connection properties and created the data model assembly, follow the steps below to start using the data model in LINQPad.

1. Open LINQPad and click Add Connection.

2. Select the "Use a typed data context from your own assembly" option.

3. Select Entity Framework DbContext.

   👁 The Choose Data Context dialog.
   

4. Click Browse next to the Path to Custom Assembly box and browse to your project folder. Browse to the .dll or .exe under the bin folder.

5. Select the name of the DbContext.
6. If you saved your connection string in App.Config, specify the path to the App.config.

You can now query PostgreSQL data through LINQPad. For examples of the supported LINQ queries, see the "LINQ and Entity Framework" chapter in the help documentation.