c# - asp.net core + ef6 + mysql

Question

我正在尝试将 EntityFramework 6 与 Asp.Net Core 一起使用来与 mysql 数据库交互。

我很难尝试仅使用代码来配置 Entity Framework ，而没有使用可在“经典”.NET MVC 项目中使用的 Web.config 中的所有配置。

我在尝试连接到数据库时遇到超时问题(我可以在另一个依赖于 Web.config 的 API 中实现这一点，因此这绝对不是网络问题)。

我目前正在使用在我的 appsettings.json 文件中定义的连接字符串实例化我的 DataContext:

  "Data": {
    "DefaultConnection": {
      "ConnectionString": "Server=db.example.com;Database=dbname;Uid=user;Pwd=123123;"
    }
  },

然后，在我的 Startup.cs 中:

        var connectionString = Configuration["Data:DefaultConnection:ConnectionString"];
        services.AddScoped((_) => new DataContext(connectionString));

此外，在 DataContext.cs 中，我使用 DbConfigurationType 装饰器设置自定义配置:

public class CodeConfig : DbConfiguration
{
    public CodeConfig()
    {
        SetDefaultConnectionFactory(new System.Data.Entity.Infrastructure.SqlConnectionFactory());
        SetProviderServices("System.Data.SqlClient",
            System.Data.Entity.SqlServer.SqlProviderServices.Instance);
        SetProviderServices("MySql.Data.MySqlClient", new MySql.Data.MySqlClient.MySqlProviderServices());

    }
}

我不是 100% 确定，但我相信问题是我从未告诉 EntityFramework 它应该使用 mysql 提供程序，而且我完全不知道应该如何执行此操作。

这是我得到的错误，也是堆栈的一部分:

SqlException: A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)

System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, SqlCredential credential, object providerInfo, string newPassword, SecureString newSecurePassword, bool redirectedUserInstance, SqlConnectionString userConnectionOptions, SessionData reconnectSessionData, DbConnectionPool pool, string accessToken, bool applyTransientFaultHandling, SqlAuthenticationProviderManager sqlAuthProviderManager)
System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection, DbConnectionOptions userOptions)
System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnectionPool pool, DbConnection owningObject, DbConnectionOptions options, DbConnectionPoolKey poolKey, DbConnectionOptions userOptions)
System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection)
System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection)
System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, uint waitForMultipleObjectsTimeout, bool allowCreate, bool onlyOneCheckConnection, DbConnectionOptions userOptions, out DbConnectionInternal connection)
System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, TaskCompletionSource<DbConnectionInternal> retry, DbConnectionOptions userOptions, out DbConnectionInternal connection)
System.Data.ProviderBase.DbConnectionFactory.TryGetConnection(DbConnection owningConnection, TaskCompletionSource<DbConnectionInternal> retry, DbConnectionOptions userOptions, DbConnectionInternal oldConnection, out DbConnectionInternal connection)
System.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource<DbConnectionInternal> retry, DbConnectionOptions userOptions)
System.Data.SqlClient.SqlConnection.TryOpenInner(TaskCompletionSource<DbConnectionInternal> retry)
System.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource<DbConnectionInternal> retry)
System.Data.SqlClient.SqlConnection.Open()
System.Data.Entity.Infrastructure.Interception.InternalDispatcher<TInterceptor>.Dispatch<TTarget, TInterceptionContext>(TTarget target, Action<TTarget, TInterceptionContext> operation, TInterceptionContext interceptionContext, Action<TInterceptor, TTarget, TInterceptionContext> executing, Action<TInterceptor, TTarget, TInterceptionContext> executed)
System.Data.Entity.Infrastructure.Interception.DbConnectionDispatcher.Open(DbConnection connection, DbInterceptionContext interceptionContext)
System.Data.Entity.SqlServer.SqlProviderServices+<>c__DisplayClass33.<UsingConnection>b__32()
System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy+<>c__DisplayClass1.<Execute>b__0()
System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute<TResult>(Func<TResult> operation)
System.Data.Entity.SqlServer.SqlProviderServices.UsingMasterConnection(DbConnection sqlConnection, Action<DbConnection> act)
System.Data.Entity.SqlServer.SqlProviderServices.CreateDatabaseFromScript(Nullable<int> commandTimeout, DbConnection sqlConnection, string createDatabaseScript)
System.Data.Entity.SqlServer.SqlProviderServices.DbCreateDatabase(DbConnection connection, Nullable<int> commandTimeout, StoreItemCollection storeItemCollection)
System.Data.Entity.Migrations.Utilities.DatabaseCreator.Create(DbConnection connection)
System.Data.Entity.Migrations.DbMigrator.EnsureDatabaseExists(Action mustSucceedToKeepDatabase)
System.Data.Entity.Migrations.DbMigrator.Update(string targetMigration)
System.Data.Entity.Internal.DatabaseCreator.CreateDatabase(InternalContext internalContext, Func<DbMigrationsConfiguration, DbContext, MigratorBase> createMigrator, ObjectContext objectContext)
System.Data.Entity.Database.Create(DatabaseExistenceState existenceState)
System.Data.Entity.CreateDatabaseIfNotExists<TContext>.InitializeDatabase(TContext context)
System.Data.Entity.Internal.InternalContext.PerformInitializationAction(Action action)
System.Data.Entity.Internal.InternalContext.PerformDatabaseInitialization()
System.Data.Entity.Internal.RetryAction<TInput>.PerformAction(TInput input)
System.Data.Entity.Internal.LazyInternalContext.InitializeDatabaseAction(Action<InternalContext> action)
System.Data.Entity.Internal.InternalContext.GetEntitySetAndBaseTypeForType(Type entityType)
System.Data.Entity.Internal.Linq.InternalSet<TEntity>.Initialize()
System.Data.Entity.Internal.Linq.InternalSet<TEntity>.get_InternalContext()
System.Data.Entity.Infrastructure.DbQuery<TResult>.System.Linq.IQueryable.get_Provider()
System.Linq.Queryable.Where<TSource>(IQueryable<TSource> source, Expression<Func<TSource, bool>> predicate)
Troco.ORM.Repository.UserRepository.GetUserInfoByLogin(string login) in UserRepository.cs

--更新--

将我的配置代码更改为:

    public class CodeConfig : DbConfiguration
    {
        public CodeConfig()
        {
            SetDefaultConnectionFactory(new MySql.Data.Entity.MySqlConnectionFactory());
            SetProviderServices("MySql.Data.MySqlClient", new MySql.Data.MySqlClient.MySqlProviderServices());

        }
    }

看来现在它尝试使用 mysql 提供程序。但是，出现此错误:

NotSupportedException: Unable to determine the provider name for provider factory of type 'MySql.Data.MySqlClient.MySqlClientFactory'. Make sure that the ADO.NET provider is installed or registered in the application config.

Answer 1

正如 @ajawad987 在他的评论中指出的那样，有必要下载并安装 Mysql Connector/NET 才能使其在没有 web.config 文件的情况下工作。

https://dev.mysql.com/downloads/connector/net/