我尝试在我的新MVC 4项目中使用自动迁移，但不知何故它没有起作用。我逐步按照这篇博客文章进行操作。
我已经对UserProfile账户模型（添加了NotaryCode字段）进行了更改：
[Table("UserProfile")]
public class UserProfile
{
[Key]
[DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
public int UserId { get; set; }
public string UserName { get; set; }
public int NotaryCode { get; set; }
}
然后我在包管理器控制台上写下enable-migrations，出现了一个配置类（继承自DbMigrationsConfiguration<Web.Models.UsersContext>），然后我将该类填充如下：
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" });
}
然后我尝试运行update-database -verbose，但是它没有起作用。我的意思是，这是输出结果：
数据库中已经存在名为'UserProfile'的对象。
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.**
我知道该对象存在。我的意思是，我正在尝试使用自动迁移来精确修改并运行数据库，而无需手动重新创建。但不知何故，这并没有起作用。
我查看了MSDN文档，并找到了该属性：
AutomaticMigrationDataLossAllowed = true;
但将其设置为true并没有改变任何内容。我想我可能漏掉了什么，但是却无法找到。有任何想法吗？