的LocalDB .mdf文件不會自動與AttachDbFileName在連接字符串

Question

我期待這種行爲，因爲this MSDN article about the AttachDbFileName property

當您第一次使用 連接字符串中這個選項連接到數據庫時，SQL連接Server Express或LocalDB實例附加 數據庫，並保持連接狀態。如果您希望將來連接到 同一數據庫，則可以使用初始目錄，但不要使用 AttachDbFileName（如果您願意）。

我有一個使用實體框架的連接字符串：

<add name="DatabaseContext" providerName="System.Data.SqlClient" connectionString="Server=(localdb)\MSSQLLocalDB;Database=DatabaseName;Integrated Security=True;AttachDbFileName=|DatabaseName|\DatabaseName.mdf" /> 

後，我打開SQL Management Studio中餵養它作爲一個額外的prameter的絕對路徑的AttachDbFileName值的數據庫能正常工作。

但是，如果我不與SQL Management Studio中連接它第一次那麼我越來越想在數據庫上運行EF遷移時出現以下錯誤：

System.Data.SqlClient.SqlException (0x80131904): Cannot create file 'C:\Users\user\Desktop\folder\DatabaseName.mdf' because it already exists. Change the file path or the file name, and retry the operation. 
CREATE DATABASE failed. Some file names listed could not be created. Check related errors. 
    at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction) 
    at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction) 
    at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose) 
    at System.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady) 
    at System.Data.SqlClient.SqlCommand.RunExecuteNonQueryTds(String methodName, Boolean async, Int32 timeout, Boolean asyncWrite) 
    at System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(TaskCompletionSource`1 completion, String methodName, Boolean sendToPipe, Int32 timeout, Boolean asyncWrite) 
    at System.Data.SqlClient.SqlCommand.ExecuteNonQuery() 
    at System.Data.Entity.Infrastructure.Interception.DbCommandDispatcher.<NonQuery>b__0(DbCommand t, DbCommandInterceptionContext`1 c) 
    at System.Data.Entity.Infrastructure.Interception.InternalDispatcher`1.Dispatch[TTarget,TInterceptionContext,TResult](TTarget target, Func`3 operation, TInterceptionContext interceptionContext, Action`3 executing, Action`3 executed) 
    at System.Data.Entity.Infrastructure.Interception.DbCommandDispatcher.NonQuery(DbCommand command, DbCommandInterceptionContext interceptionContext) 
    at System.Data.Entity.SqlServer.SqlProviderServices.<>c__DisplayClass1a.<CreateDatabaseFromScript>b__19(DbConnection conn) 
    at System.Data.Entity.SqlServer.SqlProviderServices.<>c__DisplayClass33.<UsingConnection>b__32() 
    at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.<>c__DisplayClass1.<Execute>b__0() 
    at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute[TResult](Func`1 operation) 
    at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute(Action operation) 
    at System.Data.Entity.SqlServer.SqlProviderServices.UsingConnection(DbConnection sqlConnection, Action`1 act) 
    at System.Data.Entity.SqlServer.SqlProviderServices.UsingMasterConnection(DbConnection sqlConnection, Action`1 act) 
    at System.Data.Entity.SqlServer.SqlProviderServices.CreateDatabaseFromScript(Nullable`1 commandTimeout, DbConnection sqlConnection, String createDatabaseScript) 
    at System.Data.Entity.SqlServer.SqlProviderServices.DbCreateDatabase(DbConnection connection, Nullable`1 commandTimeout, StoreItemCollection storeItemCollection) 
    at System.Data.Entity.Core.Common.DbProviderServices.CreateDatabase(DbConnection connection, Nullable`1 commandTimeout, StoreItemCollection storeItemCollection) 
    at System.Data.Entity.Core.Objects.ObjectContext.CreateDatabase() 
    at System.Data.Entity.Migrations.Utilities.DatabaseCreator.Create(DbConnection connection) 
    at System.Data.Entity.Migrations.DbMigrator.EnsureDatabaseExists(Action mustSucceedToKeepDatabase) 
    at System.Data.Entity.Migrations.DbMigrator.Update(String targetMigration) 
    at System.Data.Entity.Migrations.Infrastructure.MigratorBase.Update() 

這看起來好像它不由於某種原因自動附加數據庫，然後嘗試創建它，就好像該文件不存在一樣。

是否有額外的連接字符串選項或LocalDB配置可以解決此問題，以便數據庫自動附加到第一個連接？

Answer 1

答案很簡單：.mdf和.ldf文件是在較新版本的SQL服務器中創建的，因此舊版本不附加它們，因爲它們不存在。