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?

score 15 · Answer 1 · answered Nov 08 '13 at 19:28

15

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

answered Nov 08 '13 at 19:28

ANeves

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Up to date link for the official documentation: https://www.npgsql.org/doc/installation.html – João Portela Aug 16 '21 at 11:32

score 9 · Accepted Answer · answered Aug 02 '10 at 10:10

9

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

answered Aug 02 '10 at 10:10

Milen A. Radev

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2

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 – Earlz Aug 02 '10 at 12:45
4

This link is broken. Refer to ANeves's answer and step 4 of this article: http://www.codeproject.com/Articles/783552/Using-PostgreSQL-with-Entity-Framework-in-ASP-NET – Scotty H Aug 26 '15 at 17:41
[Actual link](https://github.com/danzel/Npgsql/blob/master/docs/UserManual.html) refers to github ;) – Maciej Los May 04 '19 at 09:18

score 1 · Answer 3 · answered Jan 11 '15 at 13:42

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

score 1 · Answer 4 · answered Dec 28 '15 at 12:54

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

score 0 · Answer 5 · answered Nov 07 '13 at 15:09

0

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

answered Nov 07 '13 at 15:09

user2965379

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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. – Colin Young Nov 07 '13 at 15:29

DbProviderFactory with Npgsql?

5 Answers5