vs2019 entityframe(EF) 连接Oracle 提示 但未在用户代码中进行处理 具有固定名称“Oracle.ManagedDataAccess.Client”的 ADO.NET 提供程序未在计算机或应用程序配置文件中注册或无法加载。

解决方法如下：

方法一、找到以下路径文件：C:WindowsMicrosoft.NETFrameworkv4.0.30319Configmachine.config

将下面这段配置文件加入<configSections>节点下。

<configSections>
    <section name="oracle.unmanageddataaccess.client" type="OracleInternal.Common.CustomSectionHandler, Oracle.DataAccess, Version=4.122.18.3, 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=4.122.18.3, Culture=neutral, PublicKeyToken=89b483f429c47342" /></configSections>

　将以下配置加入<system.data>节点下

<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=4.122.18.3, 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=4.122.18.3, Culture=neutral, PublicKeyToken=89b483f429c47342" />
    </DbProviderFactories>
 </system.data>

方法二、在vs2019 使用的config 中加入

<configSections>
    <section name="oracle.unmanageddataaccess.client" type="OracleInternal.Common.CustomSectionHandler, Oracle.DataAccess, Version=4.122.18.3, 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=4.122.18.3, Culture=neutral, PublicKeyToken=89b483f429c47342" />   
</configSections>

<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=4.122.18.3, 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=4.122.18.3, Culture=neutral, PublicKeyToken=89b483f429c47342" />
    </DbProviderFactories>
 </system.data>

注意 方法一和方法二 内容只能保留一个