entity-framework - 如何避免使用移动服务与 Azure 主数据库发生不必要的连接？

Question

以下代码:

    private void IsolateIssue()
    {
        using (var context = new SomeName.Models.MobileServiceContext())
        {
            System.Diagnostics.Debug.WriteLine(context.Database.Connection.ConnectionString);
            var numberOfItems = context.TodoItems.Count();
        }
    }

导致错误(调用 var numberOfItems 时):

An exception of type 'System.Data.SqlClient.SqlException' occurred in EntityFramework.dll but was not handled in user code Additional information: Cannot open database "master" requested by the login. The login failed. Login failed for user 'SomeLoginName'.

这是我的连接字符串:

"Data Source=ServerName.database.windows.net;Initial Catalog=SomeDataBaseName;User ID=SomeLoginName;Password=SomePassword};Asynchronous Processing=True;TrustServerCertificate=False;"

很明显无法连接master数据库。给定用户名和密码，我也无法使用 LinqPad 连接到主数据库(当我尝试时，我收到类似的错误)。但是，它根本不应该连接到主数据库。当我尝试使用 Linqpad 登录 SomeDataBaseName 时，我成功获取了 todoItems 的数量 (17)。这证明根本不需要为了给定的目的而访问主数据库。

首先，我必须确保我可以获取移动服务中的商品数量。我怎么做？初始目录显示它应该连接到 SomeDataBaseName，并且不需要连接到主数据库来获取项目数。我如何避免它尝试这样做？

如果有帮助，这里是堆栈跟踪:

StackTrace " at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action1 wrapCloseInAction)\r\n at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose)\r\n at System.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady)\r\n at System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj)\r\n at System.Data.SqlClient.SqlInternalConnectionTds.CompleteLogin(Boolean enlistOK)\r\n at System.Data.SqlClient.SqlInternalConnectionTds.AttemptOneLogin(ServerInfo serverInfo, String newPassword, SecureString newSecurePassword, Boolean ignoreSniOpenTimeout, TimeoutTimer timeout, Boolean withFailover)\r\n at System.Data.SqlClient.SqlInternalConnectionTds.LoginNoFailover(ServerInfo serverInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString connectionOptions, SqlCredential credential, TimeoutTimer timeout)\r\n at System.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(TimeoutTimer timeout, SqlConnectionString connectionOptions, SqlCredential credential, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance)\r\n at System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, SqlCredential credential, Object providerInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString userConnectionOptions, SessionData reconnectSessionData)\r\n at System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection, DbConnectionOptions userOptions)\r\n at System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnectionPool pool, DbConnection owningObject, DbConnectionOptions options, DbConnectionPoolKey poolKey, DbConnectionOptions userOptions)\r\n at System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection)\r\n at System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection)\r\n at System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, UInt32 waitForMultipleObjectsTimeout, Boolean allowCreate, Boolean onlyOneCheckConnection, DbConnectionOptions userOptions, DbConnectionInternal& connection)\r\n at System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, TaskCompletionSource1 retry, DbConnectionOptions userOptions, DbConnectionInternal& connection)\r\n at System.Data.ProviderBase.DbConnectionFactory.TryGetConnection(DbConnection owningConnection, TaskCompletionSource1 retry, DbConnectionOptions userOptions, DbConnectionInternal oldConnection, DbConnectionInternal& connection)\r\n at System.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource1 retry, DbConnectionOptions userOptions)\r\n at System.Data.ProviderBase.DbConnectionClosed.TryOpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource1 retry, DbConnectionOptions userOptions)\r\n at System.Data.SqlClient.SqlConnection.TryOpenInner(TaskCompletionSource1 retry)\r\n at System.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource1 retry)\r\n at System.Data.SqlClient.SqlConnection.Open()\r\n at System.Data.Entity.Infrastructure.Interception.DbConnectionDispatcher.<Open>b__36(DbConnection t, DbConnectionInterceptionContext c)\r\n at System.Data.Entity.Infrastructure.Interception.InternalDispatcher1.Dispatch[TTarget,TInterceptionContext](TTarget target, Action2 operation, TInterceptionContext interceptionContext, Action3 executing, Action3 executed)\r\n at System.Data.Entity.Infrastructure.Interception.DbConnectionDispatcher.Open(DbConnection connection, DbInterceptionContext interceptionContext)\r\n at System.Data.Entity.SqlServer.SqlProviderServices.<>c__DisplayClass34.<UsingConnection>b__32()\r\n at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.<>c__DisplayClass1.<Execute>b__0()\r\n at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute[TResult](Func1 operation)\r\n at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute(Action operation)\r\n at System.Data.Entity.SqlServer.SqlProviderServices.UsingConnection(DbConnection sqlConnection, Action1 act)\r\n at System.Data.Entity.SqlServer.SqlProviderServices.UsingMasterConnection(DbConnection sqlConnection, Action1 act)\r\n at System.Data.Entity.SqlServer.SqlProviderServices.DropDatabase(SqlConnection sqlConnection, Nullable1 commandTimeout, String databaseName)\r\n at System.Data.Entity.SqlServer.SqlProviderServices.DbDeleteDatabase(DbConnection connection, Nullable1 commandTimeout, StoreItemCollection storeItemCollection)\r\n at System.Data.Entity.Core.Common.DbProviderServices.DeleteDatabase(DbConnection connection, Nullable1 commandTimeout, StoreItemCollection storeItemCollection)\r\n at System.Data.Entity.Core.Objects.ObjectContext.DeleteDatabase()\r\n at System.Data.Entity.Internal.DatabaseOperations.Delete(ObjectContext objectContext)\r\n at System.Data.Entity.Database.Delete()\r\n at System.Data.Entity.DropCreateDatabaseIfModelChanges1.InitializeDatabase(TContext context)\r\n at System.Data.Entity.Internal.InternalContext.<>c__DisplayClassf1.<CreateInitializationAction>b__e()\r\n at System.Data.Entity.Internal.InternalContext.PerformInitializationAction(Action action)\r\n at System.Data.Entity.Internal.InternalContext.PerformDatabaseInitialization()\r\n at System.Data.Entity.Internal.LazyInternalContext.<InitializeDatabase>b__4(InternalContext c)\r\n at System.Data.Entity.Internal.RetryAction1.PerformAction(TInput input)\r\n at System.Data.Entity.Internal.LazyInternalContext.InitializeDatabaseAction(Action1 action)\r\n at System.Data.Entity.Internal.LazyInternalContext.InitializeDatabase()\r\n at System.Data.Entity.Internal.InternalContext.GetEntitySetAndBaseTypeForType(Type entityType)\r\n at System.Data.Entity.Internal.Linq.InternalSet1.Initialize()\r\n at System.Data.Entity.Internal.Linq.InternalSet1.get_InternalContext()\r\n at System.Data.Entity.Infrastructure.DbQuery1.System.Linq.IQueryable.get_Provider()\r\n at System.Linq.Queryable.Count[TSource](IQueryable`1 source)\r\n

Answer 1

我在您的堆栈中看到了这个:System.Data.Entity.DropCreateDatabaseIfModelChanges。我相信 EF 需要访问主数据库才能删除并重新创建您的数据库。

这篇博文提到了 ClearDatabaseSchemaIfModelChanges 初始化程序，它可能会执行您想要的操作:http://blogs.msdn.com/b/azuremobile/archive/2014/06/07/fresh-updates-to-azure-mobile-services-net.aspx