ASP.NET SimpleMembershipProvider 的自動遷移

所以我嘗試在我的新 MVC 4 項目中使用自動遷移，但不知何故它不起作用。我一步一步地關注了這篇博文。

我已將更改添加到UserProfile帳戶模型（NotaryCode欄位）：

[Table("UserProfile")]
public class UserProfile
{
   [Key]
   [DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
   public int UserId { get; set; }
   public string UserName { get; set; }
   public int NotaryCode { get; set; }
}

然後我在包管理器控制台上寫了enable-migrations一個配置類（從 繼承DbMigrationsConfiguration<Web.Models.UsersContext>）然後我將類填充為：

public Configuration()
{
   AutomaticMigrationsEnabled = true;
}

protected override void Seed(Atomic.Vesper.Cloud.Web.Models.UsersContext context)
{
   WebSecurity.InitializeDatabaseConnection(
           "DefaultConnection",
           "UserProfile",
           "UserId",
           "UserName", autoCreateTables: true);

   if (!Roles.RoleExists("Atomic"))
       Roles.CreateRole("Atomic");

   if (!Roles.RoleExists("Protocolista"))
       Roles.CreateRole("Protocolista");

   if (!Roles.RoleExists("Cliente"))
       Roles.CreateRole("Cliente");

   string adminUser = "randolf";

   if (!WebSecurity.UserExists(adminUser))
       WebSecurity.CreateUserAndAccount(
           adminUser,
           "12345",
           new { NotaryCode = -1 });

   if (!Roles.GetRolesForUser(adminUser).Contains("Atomic"))
       Roles.AddUsersToRoles(new[] { adminUser }, new[] { "Atomic" });
}

然後我嘗試執行update-database -verbose，但這不起作用。我的意思是，這是輸出：

數據庫中已經有一個名為“UserProfile”的對象。

PM> update-database -verbose
Using StartUp project 'Web'.
Using NuGet project 'Web'.
Specify the '-Verbose' flag to view the SQL statements being applied to the target database.
Target database is: 'VesperCloud' (DataSource: .\SQLSERVER, Provider: System.Data.SqlClient, Origin: Configuration).
No pending code-based migrations.
Applying automatic migration: 201211051825098_AutomaticMigration.
CREATE TABLE [dbo].[UserProfile] (
   [UserId] [int] NOT NULL IDENTITY,
   [UserName] [nvarchar](max),
   [NotaryCode] [int] NOT NULL,
   CONSTRAINT [PK_dbo.UserProfile] PRIMARY KEY ([UserId])
)
System.Data.SqlClient.SqlException (0x80131904): There is already an object named 'UserProfile' in the database.
  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)
  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.Migrations.DbMigrator.ExecuteSql(DbTransaction transaction, MigrationStatement migrationStatement)
  at System.Data.Entity.Migrations.Infrastructure.MigratorLoggingDecorator.ExecuteSql(DbTransaction transaction, MigrationStatement migrationStatement)
  at System.Data.Entity.Migrations.DbMigrator.ExecuteStatements(IEnumerable`1 migrationStatements)
  at System.Data.Entity.Migrations.Infrastructure.MigratorBase.ExecuteStatements(IEnumerable`1 migrationStatements)
  at System.Data.Entity.Migrations.DbMigrator.ExecuteOperations(String migrationId, XDocument targetModel, IEnumerable`1 operations, Boolean downgrading, Boolean auto)
  at System.Data.Entity.Migrations.DbMigrator.AutoMigrate(String migrationId, XDocument sourceModel, XDocument targetModel, Boolean downgrading)
  at System.Data.Entity.Migrations.Infrastructure.MigratorLoggingDecorator.AutoMigrate(String migrationId, XDocument sourceModel, XDocument targetModel, Boolean downgrading)
  at System.Data.Entity.Migrations.DbMigrator.Upgrade(IEnumerable`1 pendingMigrations, String targetMigrationId, String lastMigrationId)
  at System.Data.Entity.Migrations.Infrastructure.MigratorLoggingDecorator.Upgrade(IEnumerable`1 pendingMigrations, String targetMigrationId, String lastMigrationId)
  at System.Data.Entity.Migrations.DbMigrator.Update(String targetMigration)
  at System.Data.Entity.Migrations.Infrastructure.MigratorBase.Update(String targetMigration)
  at System.Data.Entity.Migrations.Design.ToolingFacade.UpdateRunner.RunCore()
  at System.Data.Entity.Migrations.Design.ToolingFacade.BaseRunner.Run()
ClientConnectionId:a7da0ddb-bccf-490f-bc1e-ecd2eb4eab04
**There is already an object named 'UserProfile' in the database.**

我知道對象存在。我的意思是，我嘗試使用自動遷移來精確地修改和執行，而無需手動重新創建數據庫。但不知何故，這不起作用。

我查看了 MSDN 文件並找到了該屬性：

AutomaticMigrationDataLossAllowed = true;

但是將其設置為 true 並不會改變任何事情。我想我錯過了一些東西，但不知何故找不到什麼。任何想法？

update-database -verbose不起作用，因為在您的數據表已經存在之後您的模型已更改。

首先，確保 UserProfile 類沒有更改。然後，執行：

Add-Migration InitialMigrations -IgnoreChanges

這應該會生成一個空白的“InitialMigration”文件。現在，向 UserProfile 類添加任何所需的更改。添加更改後，再次執行更新命令：

update-database -verbose

現在將應用自動遷移，並且表格將隨著您的更改而更改。

引用自：https://stackoverflow.com/questions/13238203