However, the user code does not process the ADO. NET provider with a fixed name "Oracle. ManagedDataAccess. Client". It is not registered in the computer or application configuration file or cannot be loaded .,

However, the user code does not process the ADO. NET provider with a fixed name "Oracle. ManagedDataAccess. Client". It is not registered in the computer or application configuration file or cannot be loaded .,

This is a common error in connecting to the Orcl database using ODP. NET. You need to configure system environment variables.

The solution is as follows:

Find the following path file: C: \ Windows \ Microsoft. NET \ Framework \ v4.0.30319 \ Config \ machine. config

Note: It is best to back up data before modification to avoid ....

Add the following configuration file to the <configSections> node.

<configSections>    <section name="oracle.unmanageddataaccess.client" type="OracleInternal.Common.CustomSectionHandler, Oracle.DataAccess, Version=4.121.2.0, Culture=neutral, PublicKeyToken=89b483f429c47342" />    <section name="oracle.dataaccess.client" type="System.Data.Common.DbProviderConfigurationHandler, System.Data, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />    <section name="oracle.manageddataaccess.client" type="OracleInternal.Common.ODPMSectionHandler, Oracle.ManagedDataAccess, Version=4.121.2.0, Culture=neutral, PublicKeyToken=89b483f429c47342" />    ................
    ................</configSections>

Add the following configurations to the <system. data> node:

<system.data>    <DbProviderFactories>      <add name="ODP.NET, Unmanaged Driver" invariant="Oracle.DataAccess.Client" description="Oracle Data Provider for .NET, Unmanaged Driver" type="Oracle.DataAccess.Client.OracleClientFactory, Oracle.DataAccess, Version=4.121.2.0, Culture=neutral, PublicKeyToken=89b483f429c47342" />      <add name="ODP.NET, Managed Driver" invariant="Oracle.ManagedDataAccess.Client" description="Oracle Data Provider for .NET, Managed Driver" type="Oracle.ManagedDataAccess.Client.OracleClientFactory, Oracle.ManagedDataAccess, Version=4.121.2.0, Culture=neutral, PublicKeyToken=89b483f429c47342" />    </DbProviderFactories> </system.data>