将 SQL Server 与 MySQL 一起使用时出现“不支持的选项”错误

Question

我试图在同一个控制台应用程序上从 MySQL 和 SQL Server 检索数据。我设法从 MySQL 检索数据，但是当我尝试从 SQL Server 检索数据时，出现System.ArgumentException: 'Option not supported. Parameter name: multipleactiveresultsets'错误。以下是我的app.config：<?xml version="1.0" encoding="utf-8" ?><configuration>  <configSections>    <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />  </configSections>  <startup>    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.1" />  </startup>  <connectionStrings>    <add name="MySQLDb" providerName="MySql.Data.MySqlClient" connectionString="server=localhost;port=3306;database=sakila;uid=some_user;password=some_password"/>    <add name="SQLDb" providerName="System.Data.SqlClient" connectionString="data source=USER-PC\SQLEXPRESS;initial catalog=MyDatabase;integrated security=True;MultipleActiveResultSets=True;App=EntityFramework"/>  </connectionStrings>  <entityFramework codeConfigurationType="MySql.Data.Entity.MySqlEFConfiguration, MySql.Data.Entity.EF6">    <defaultConnectionFactory type="System.Data.Entity.Infrastructure.SqlConnectionFactory, EntityFramework"/>    <providers>      <provider invariantName="MySql.Data.MySqlClient" type="MySql.Data.MySqlClient.MySqlProviderServices, MySql.Data.Entity.EF6"/>      <provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer"/>    </providers>  </entityFramework></configuration>还有我的 C#：#region MySQL.{    var dbContext = new MySQLDb();    var dbSet = dbContext.Set<Actor>();    var actors = dbSet.ToList();}#endregion#region SQLServer.{    var dbContext = new SQLDb();    var dbSet = dbContext.Set<User>();    var users = dbSet.ToList(); // <-- Throw exception.}#endregion如果我在 C# 代码中禁用entityFrameworksection inapp.config和 MySQL 代码块，我可以毫无问题地从 SQL Server 检索数据。版本信息

Answer 1

问题是我们正在使用MySql.Data.Entity.MySqlEFConfiguration（在 中app.config）将默认连接工厂设置为使用MySqlConnectionFactory。

解决方案是使用自定义DbConfiguration代替MySql.Data.Entity.MySqlEFConfiguration来阻止设置默认连接工厂。

public class MySQLDbConfiguration : DbConfiguration

{

    public MySQLDbConfiguration()

    {

        SetProviderServices(MySqlProviderInvariantName.ProviderName, new MySqlProviderServices());

        SetProviderFactory(MySqlProviderInvariantName.ProviderName, new MySqlClientFactory());

    }

}

在代码中的某处将实例声明为只读，

private static readonly MySQLDbConfiguration DBConfig = new MySQLDbConfiguration();

并在使用任何 EF 功能之前设置配置

DbConfiguration.SetConfiguration(DBConfig);

而我们的app.config现在变成

<?xml version="1.0" encoding="utf-8" ?>

<configuration>

  <startup>

    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.1" />

  </startup>

  <connectionStrings>

    <add name="MySQLDb" providerName="MySql.Data.MySqlClient" connectionString="server=localhost;port=3306;database=sakila;uid=some_user;password=some_password"/>

    <add name="SQLDb" providerName="System.Data.SqlClient" connectionString="data source=USER-PC\SQLEXPRESS;initial catalog=MyDatabase;integrated security=True;MultipleActiveResultSets=True;App=EntityFramework"/>

  </connectionStrings>

</configuration>

如果您选择使用app.config而不是派生自定义DbConfiguration，则可以执行以下操作

<?xml version="1.0" encoding="utf-8" ?>

<configuration>

  <!-- Alternative to custom DbConfiguration. -->

  <configSections>

    <section name = "entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />

  </configSections>

  <entityFramework>

    <providers>

      <provider invariantName = "MySql.Data.MySqlClient" type="MySql.Data.MySqlClient.MySqlProviderServices, MySql.Data.Entity.EF6"/>

    </providers>

  </entityFramework>

  <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=6.10.8.0, Culture=neutral, PublicKeyToken=c5687fc88969c44d"/>

    </DbProviderFactories>

  </system.data>

  <startup>

    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.1" />

  </startup>

  <connectionStrings>

    <add name="MySQLDb" providerName="MySql.Data.MySqlClient" connectionString="server=localhost;port=3306;database=sakila;uid=some_user;password=some_password"/>

    <add name="SQLDb" providerName="System.Data.SqlClient" connectionString="data source=USER-PC\SQLEXPRESS;initial catalog=MyDatabase;integrated security=True;MultipleActiveResultSets=True;App=EntityFramework"/>

  </connectionStrings>

</configuration>

Answer 2

如果您使用的是 asp net 5.0，请安装此处找到的 Nuget ，但首先要卸载 Mysql.data。