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The specified invariant name 'MySql.Data.MySqlClient' wasn't found in the list of registered .NET Data Providers

I have a C# Library developed using .Net Standard 2.1 and this library is called in a test console application built on .Net Core 3.0. But at run time, the GetFactory is throwing an exception.
private DbConnection connection;
connection = DbProviderFactories.GetFactory("MySql.Data.MySqlClient").CreateConnection();
Exception:
DbProviderFactories.GetFactory The specified invariant name 'MySql.Data.MySqlClient' wasn't found in the list of registered .NET Data Providers.
I have installed MySqlConnector 1.2.1. But it didn't help. And also adding the below in app.config file.
<system.data>
<DbProviderFactories>
<remove invariant="MySql.Data.MySqlClient" />
<add name="MySQL Data Provider" invariant="MySql.Data.MySqlClient" description=".Net Framework Data Provider for MySQL" type="MySql.Data.MySqlClient.MySqlClientFactory, MySql.Data, Version=8.0.23.0, Culture=neutral, PublicKeyToken=c5687fc88969c44d" />
</DbProviderFactories>
</system.data>
Thanks in advance for your help.

The XML you've shown for app.config only works in .NET Framework applications.
For .NET Core 2.1 or later, call DbProviderFactories.RegisterFactory. The exact arguments you pass will depend on the factory you want to register (and the NuGet packages you have installed):
// MySqlConnector (my personal recommendation for .NET Core)
DbProviderFactories.RegisterFactory("MySqlConnector", MySqlConnector.MySqlConnectorFactory.Instance);
// MySql.Data (may be needed instead if other code is hard-coded to "MySql.Data.MySqlClient")
DbProviderFactories.RegisterFactory("MySql.Data.MySqlClient", MySql.Data.MySqlClient.MySqlClientFactory.Instance);
For more information, see Using DbProviderFactories.

MySQL Provider errors in Entity Framework 5.0

I'm using Entity Framework 5.0 with MySQL 6.8.3
I've already copy both MySql.Data.dll and MySql.Data.Entity.dll to Output folder.
On my PC, I add following code to App.Config:
<system.data>
<DbProviderFactories>
<remove invariant="MySql.Data.MySqlClient"/>
<add name="MySQL Data Provider" invariant="MySql.Data.MySqlClient" description=".Net Framework Data Provider for MySQL" type="MySql.Data.MySqlClient.MySqlClientFactory, MySql.Data"/>
</DbProviderFactories>
</system.data>
It works fine, but when I bring it to another PC, I must remove that config to make it worked. How can I make it worked without adding or removing that config?

I've figured out my problem. This issue was due to conflict of MySQL in project and Connector/Net.
For anyone has the same problem with me, just specific the version of MySQL dll in your provider configuration:
<system.data>
<DbProviderFactories>
<remove invariant="MySql.Data.MySqlClient"/>
<add name="MySQL Data Provider" invariant="MySql.Data.MySqlClient" description=".Net Framework Data Provider for MySQL" type="MySql.Data.MySqlClient.MySqlClientFactory, MySql.Data, Version=6.8.3.0, Culture=neutral, PublicKeyToken=c5687fc88969c44d"/>
</DbProviderFactories>
</system.data>
This version should be same as the dll that your project references.

Connection to PostgreSQL DB failure

I am currently working on a 3.5 .NET C# Project. it uses an external program that takes an argument when I build and run it. The external program goes to index a structured or an unstructured source of data.
The C# project is a simple .dll that override some of the external program methods. At the initialization part, I do request a connection to my postgreSQL DB in order to get back a unique ID.
WARNING : Indexer and my DB have no link, Indexer can index folder with .xls files, or mysql DB. My PostgreSQL is here just to bring a unique ID and store some important informations
My problem is when I launch as an external program the DBConnector which is a 32 bit indexer, everything goes well.
Whereas when I launch the AlfrescoConnector which is a 64 bit indexer, I can't open my postgreSQL database.
I put the x86 & x64 type of connector but I don't know if the problem comes from there.
I'm working on Visual 2012, my debug is set to produce a x86 compatible program (changing it to "any CPU" or "x64" doesn't solve the problem)
The db object I use is DbClient which is a specific method that you won't find on the internet because it comes from the external program reference, but it works as a classic DbConnector.
My DbClient object looks like this :
dbClient = {Sinequa.Common.DbClient}
_CurrentTransaction = null
ConnectionString = "Server=localhost;Port=5444;User Id=USERSAMPLE;Database=DBSAMPLE;Password=PWDSAMPLE;"
DbCn = null
DbCnSubSelect = null
DbFactory = null
DbIsolationLevel = Unspecified
DefaultCommandBehavior = SequentialAccess
Engine = Postgres
Error = 0
ErrorText = null
LastRowAffected = 0
LOBFetchSize = 0
Provider = "Npgsql"
RefreshCount = 0
RefreshCurrent = 0
Schema = null
The error comes when I do myDbClient.Open() with the Alfresco one
Any suggestions ? Need more details ? I'm ready to solve this painful error with you my fellows !

The Alfresco x64 bit connector use the x64 bit of the .NET configuration file. The configuration files located at:
C:\Windows\Microsoft.NET\Framework\v2.0.50727\CONFIG\machine.conf
C:\Windows\Microsoft.NET\Framework\v4.0.30319\Config\machine.conf
C:\Windows\Microsoft.NET\Framework64\v2.0.50727\CONFIG\machine.conf
C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Config\machine.conf
Remember that the problem is the missing provider. So to solve this problem you have to insert the lacking provider between the DbProviderFactories tag like this:
<DbProviderFactories>
<add name="Odbc Data Provider" invariant="System.Data.Odbc" description=".Net Framework Data Provider for Odbc" type="System.Data.Odbc.OdbcFactory, System.Data, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>
<add name="OleDb Data Provider" invariant="System.Data.OleDb" description=".Net Framework Data Provider for OleDb" type="System.Data.OleDb.OleDbFactory, System.Data, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>
<add name="OracleClient Data Provider" invariant="System.Data.OracleClient" description=".Net Framework Data Provider for Oracle" type="System.Data.OracleClient.OracleClientFactory, System.Data.OracleClient, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>
<add name="SqlClient Data Provider" invariant="System.Data.SqlClient" description=".Net Framework Data Provider for SqlServer" type="System.Data.SqlClient.SqlClientFactory, System.Data, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>
<add name="Npgsql Data Provider" invariant="Npgsql" description=".Net Framework Data Provider for PostgreSQL" type="Npgsql.NpgsqlFactory, Npgsql, Version=2.0.13.91, Culture=neutral, PublicKeyToken=5d8b90d52f46fda7"/>
<add name="MySQL Data Provider" invariant="MySql.Data.MySqlClient" description=".Net Framework Data Provider for MySQL" type="MySql.Data.MySqlClient.MySqlClientFactory, MySql.Data, Version=6.5.4.0, Culture=neutral, PublicKeyToken=c5687fc88969c44d"/>
<add name="Microsoft SQL Server Compact Data Provider 4.0" invariant="System.Data.SqlServerCe.4.0" description=".NET Framework Data Provider for Microsoft SQL Server Compact" type="System.Data.SqlServerCe.SqlCeProviderFactory, System.Data.SqlServerCe, Version=4.0.0.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91"/>
</DbProviderFactories>
With this insert the next time the DbClient will try to open the Database and get the asked provider, it will succeed.

How do I set the absolute path for a assembly containing Database connector? MySQL Connector 6.4.3 with Entity Framework 4.1

Reason why: http://bugs.mysql.com/bug.php?id=61933
I recompiled the connector from source, incremented tit a version to 6.4.3.1, but now this (possibly) trivial question blocks me.
How do I set the full provider name in the connection string in app.config? I have the official 6.4.3 connector installed.
The error I get is when I add a new entity data model, and select from an existing database. This I traced to the above linked (silly) bug.
I couldn't find a better title for this question.
Microsoft Visual Studio
An error occurred while connecting to the database. The database might be unavailable. An exception of type 'System.Data.ProviderIncompatibleException' occurred. The error message is: 'The provider did not return a ProviderManifestToken string.
The inner exception caught was of type 'System.FormatException', with this error message: 'Input string was not in a correct format.'.'.
OK
Solution
Download MySQL Connector/6.4.3 sources, and extract it.
In the MySql.Data.Entity project, replace...:
(ProviderServices.cs:188) With: double version = double.Parse(connection.ServerVersion.Substring(0, 3), System.Globalization.CultureInfo.InvariantCulture);
(ProviderManifest.cs:73) With: double version = double.Parse(manifestToken, System.Globalization.CultureInfo.InvariantCulture);
Create a new sign key and name it ConnectorNet (same name as in the assemblyinfo.cs)
Add .1 to the AssemblyVersion in AssemblyInfo.cs in the MySql.Data project, this 1 file is shared with the rest: [assembly: AssemblyVersion("6.4.3.1")]
Put Release as target configuration, you can also disable the .Tests projects from being built.
As admin, install them with gacutil. Here you also get the public key token.
Locate Machine.config note it is important to know what .NET fx you compiled the project(s) to use.
Search for DbProviderFactories, and comment out the existing MySQL Data Provider, copy it and replace in the duplicate entry, by adding the .1 in version and the public key token.
<!-- add name="MySQL Data Provider" invariant="MySql.Data.MySqlClient" description=".Net Framework Data Provider for MySQL" type="MySql.Data.MySqlClient.MySqlClientFactory, MySql.Data, Version=6.4.3.0, Culture=neutral, PublicKeyToken=c5687fc88969c44d" / -->
<add name="MySQL Data Provider" invariant="MySql.Data.MySqlClient" description=".Net Framework Data Provider for MySQL" type="MySql.Data.MySqlClient.MySqlClientFactory, MySql.Data, Version=6.4.3.1, Culture=neutral, PublicKeyToken=XXXXXXXXXXXXXXX" />

Connection string doesn't contain path to provider assembly. Connection string's providerName is only reference to provider registered in system.data\DbProviderFactories:
<system.data>
<DbProviderFactories>
<remove invariant="MySql.Data.MySqlClient" />
<add name="MySQL Data Provider"
invariant="MySql.Data.MySqlClient"
description=".Net Framework Data Provider for MySQL"
type="MySql.Data.MySqlClient.MySqlClientFactory, MySql.Data, Version=6.4.3.1, Culture=neutral, PublicKeyToken=YourToken" />
</system.data>
The invariant from factory registration is what you reference in providerName of connection string. You can try to put your new connector assembly to your application directory or strongly name the assembly install it to GAC.

Simpler solution: use the official 6.4.3 installer.
Go in your regional settings, change your decimal separator from ',' to '.' et voilà.
It's enough while waiting for the 6.4.4 to ship.

Oracle data provider (ODP.NET) not listed in DbProviderFactories

I want to use the DbProvider class to construct a generic DAL component. This will be convenient when switching between different database providers.
On a machine with Oracle 2.2 installed the Oracle provider ODP.NET is not listed when trying to list up all the database providers available on the machine.
DataTable dtable = DbProviderFactories.GetFactoryClasses();
Though referencing the Oracle.DataAccess.dll and connect to Oracle using the OracleConnection class is not problem.
OracleConnection con = new OracleConnection();
What am I doing wrong here ?
EDIT:
According to this page I should see an "Oracle Data Provider for .Net" in the list.

Here is how DbProviderFactories.GetFactoryClasses works...
By default, (if you don't have an app.config), it will look in your machine.config for a section called system.data/DBProviderFactories. Basically all "registered" db provider that will be accessabile can be found in that section.
So either add that to your app.config system.data/DBProviderFactories section or to the machine.config.
something like:
<configuration>
<system.data>
<DbProviderFactories>
<add name="Oracle Data Provider for .NET" invariant="Oracle.DataAccess.Client" description=".Net Framework Data Provider for Oracle" type="Oracle.DataAccess.Client.OracleClientFactory, Oracle.DataAccess, Version=10.2.0.100, Culture=neutral, PublicKeyToken=89b483f429c47342" />
</DbProviderFactories>
</system.data>
</configuration>
And make sure your ODP.NET version support DbProviderFactories. I think you need Oracle Database 10g Release 2 to do this.

Executing your code I see the following row in my datatable:
OracleClient Data Provider .Net Framework Data Provider for Oracle
System.Data.OracleClient System.Data.OracleClient.OracleClientFactory,
System.Data.OracleClient, Version=2.0.0.0, Culture=neutral,
PublicKeyToken=b77a5c561934e089
System.Data.OracleClient should be in your GAC as of .NET Framework 2.0