DbProviderFactory with Npgsql?

Question

I have a project which I'm trying to port from SQL Server to PostgreSQL. I've got almost everything done I believe except for I can not get DbProviderFactory to work with Npgsql.

Factory = DbProviderFactories.GetFactory("Npgsql");

yields

Unhandled Exception: System.Configuration.ConfigurationErrorsException: Failed to find or load the registered .Net Framework Data Provider.

How do I fix this?

Veronikaveronike

Answer 1

Have you read section 3.4 "Using Npgsql with ProviderFactory" from the fine manual?

Natatorial

Actually I read it and adding it to machine.config didn't work. I checked and the version that comes with Mono for Arch Linux(2.0.0.0) didn't support it. I upgraded to the latest version and now everything is good – Veronikaveronike

This link is broken. Refer to ANeves's answer and step 4 of this article: codeproject.com/Articles/783552/… – Fanestil

Actual link refers to github ;) – Loverly

Answer 2

Try defining a factory in your app.config:

<system.data>
  <DbProviderFactories>
    <add name="Npgsql Data Provider" invariant="Npgsql"
         description="Data Provider for PostgreSQL"
         type="Npgsql.NpgsqlFactory, Npgsql" />
  </DbProviderFactories>
</system.data>

Via http://fxjr.blogspot.pt/2013/06/npgsql-code-first-entity-framework-431.html

Townscape

Up to date link for the official documentation: npgsql.org/doc/installation.html – Whiffen

Answer 3

The type attribute value is important in the DbProviderFactories entry.

For me, the version number was incorrect. Correct version was :

<system.data>
  <DbProviderFactories>
    <add name="Npgsql Data Provider" 
         invariant="Npgsql" 
         support="FF" 
         description=".Net Framework Data Provider for Postgresql Server" 
         type="Npgsql.NpgsqlFactory, Npgsql, Version=2.2.3.0, Culture=neutral, PublicKeyToken=5d8b90d52f46fda7" />
  </DbProviderFactories>
</system.data>

You can retrieve the value on your project with :

typeof(Npgsql.NpgsqlFactory).AssemblyQualifiedName

Airburst

Answer 4

These were the steps that resolved it for me:

(1) add DbFactory provider to machine.config file located in the .NET Microsoft Frameworking folder

(2) register npgsql.dll and mono.security.dll in GAC using gacutil

---

Step by step details for:

(1) add DbFactory provider to machine.config

a. go to your relevant NET framework config directory (e.g. C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Config)

b. edit the machine.config file and add the below line to DbProviderFactories

<DbProviderFactories>
    <add name="Npgsql Data Provider" 
         invariant="Npgsql" 
         support="FF" 
         description=".Net Framework Data Provider for Postgresql Server" 
         type="Npgsql.NpgsqlFactory, Npgsql"/>
  </DbProviderFactories>

(2) register npgsql.dll and mono.security.dll in GAC

a. check if npgsql and mono.security is in GAC folder (my GAC folder was located at C:\Windows\Microsoft.NET\assembly\GAC_MSIL)

If not, then use gacutil to install npgsql to GAC in command prompt using gacutil /i npgsql.dll

Sakhuja

Answer 5

register ngsql and mono.security dll in GAC and add dbfactory provider in machine.config for both[32 & 64 bit version ]

Tammeratammi

This answer could be more useful with some code examples to illustrate how to register assemblies in the GAC and how to modify machine.config, along with how to locate them. – Resonate