There is already an object named in the database как исправить

Update-Database failed from Package Manager Console.
I’ve used Entity Framework 6.x and code-first approach.
Error is

«There is already an object named ‘AboutUs’ in the database.»

How can I solve this problem?

internal sealed class Configuration 
    : DbMigrationsConfiguration<Jahan.Blog.Web.Mvc.Models.JahanBlogDbContext>
{
    public Configuration()
    {
        AutomaticMigrationsEnabled = true;
        AutomaticMigrationDataLossAllowed = false;
    }

    protected override void Seed(Jahan.Blog.Web.Mvc.Models.JahanBlogDbContext context)
    {

    }
}

My DbContext is:

public class JahanBlogDbContext : IdentityDbContext<User, Role, int, UserLogin, UserRole, UserClaim>
{
    public JahanBlogDbContext()
        : base("name=JahanBlogDbConnectionString")
    {
        Database.SetInitializer(new DropCreateDatabaseIfModelChanges<JahanBlogDbContext>());
    }
    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();
        modelBuilder.Entity<Comment>().HasRequired(t => t.Article).WithMany(t => t.Comments).HasForeignKey(d => d.ArticleId).WillCascadeOnDelete(true);
        base.OnModelCreating(modelBuilder);

        modelBuilder.Entity<User>().ToTable("User");
        modelBuilder.Entity<Role>().ToTable("Role");
        modelBuilder.Entity<UserRole>().ToTable("UserRole");
        modelBuilder.Entity<UserLogin>().ToTable("UserLogin");
        modelBuilder.Entity<UserClaim>().ToTable("UserClaim");
    }

    public virtual DbSet<Article> Articles { get; set; }
    public virtual DbSet<ArticleLike> ArticleLikes { get; set; }
    public virtual DbSet<ArticleTag> ArticleTags { get; set; }
    public virtual DbSet<AttachmentFile> AttachmentFiles { get; set; }
    public virtual DbSet<Comment> Comments { get; set; }
    public virtual DbSet<CommentLike> CommentLikes { get; set; }
    public virtual DbSet<CommentReply> CommentReplies { get; set; }
    public virtual DbSet<ContactUs> ContactUs { get; set; }
    public virtual DbSet<Project> Projects { get; set; }
    public virtual DbSet<ProjectState> ProjectStates { get; set; }
    public virtual DbSet<ProjectTag> ProjectTags { get; set; }
    public virtual DbSet<Rating> Ratings { get; set; }
    public virtual DbSet<Tag> Tags { get; set; }
    public virtual DbSet<AboutUs> AboutUs { get; set; }
}

Package Manage Console:

PM> update-database -verbose -force
Using StartUp project 'Jahan.Blog.Web.Mvc'.
Using NuGet project 'Jahan.Blog.Web.Mvc'.
Specify the '-Verbose' flag to view the SQL statements being applied to the target database.
Target database is: 'Jahan-Blog' (DataSource: (local), Provider: System.Data.SqlClient, Origin: Configuration).
No pending explicit migrations.
Applying automatic migration: 201410101740197_AutomaticMigration.
CREATE TABLE [dbo].[AboutUs] (
    [Id] [int] NOT NULL IDENTITY,
    [Description] [nvarchar](max),
    [IsActive] [bit] NOT NULL,
    [CreatedDate] [datetime],
    [ModifiedDate] [datetime],
    CONSTRAINT [PK_dbo.AboutUs] PRIMARY KEY ([Id])
)
System.Data.SqlClient.SqlException (0x80131904): There is already an object named 'AboutUs' 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, 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.Internal.InterceptableDbCommand.ExecuteNonQuery()
   at System.Data.Entity.Migrations.DbMigrator.ExecuteSql(DbTransaction transaction, MigrationStatement migrationStatement, DbInterceptionContext interceptionContext)
   at System.Data.Entity.Migrations.Infrastructure.MigratorLoggingDecorator.ExecuteSql(DbTransaction transaction, MigrationStatement migrationStatement, DbInterceptionContext interceptionContext)
   at System.Data.Entity.Migrations.DbMigrator.ExecuteStatementsInternal(IEnumerable`1 migrationStatements, DbTransaction transaction, DbInterceptionContext interceptionContext)
   at System.Data.Entity.Migrations.DbMigrator.ExecuteStatementsInternal(IEnumerable`1 migrationStatements, DbConnection connection)
   at System.Data.Entity.Migrations.DbMigrator.<>c__DisplayClass30.<ExecuteStatements>b__2e()
   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.Migrations.DbMigrator.ExecuteStatements(IEnumerable`1 migrationStatements, DbTransaction existingTransaction)
   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, IEnumerable`1 systemOperations, Boolean downgrading, Boolean auto)
   at System.Data.Entity.Migrations.DbMigrator.AutoMigrate(String migrationId, VersionedModel sourceModel, VersionedModel targetModel, Boolean downgrading)
   at System.Data.Entity.Migrations.Infrastructure.MigratorLoggingDecorator.AutoMigrate(String migrationId, VersionedModel sourceModel, VersionedModel 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.UpdateInternal(String targetMigration)
   at System.Data.Entity.Migrations.DbMigrator.<>c__DisplayClassc.<Update>b__b()
   at System.Data.Entity.Migrations.DbMigrator.EnsureDatabaseExists(Action mustSucceedToKeepDatabase)
   at System.Data.Entity.Migrations.Infrastructure.MigratorBase.EnsureDatabaseExists(Action mustSucceedToKeepDatabase)
   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.Run()
   at System.AppDomain.DoCallBack(CrossAppDomainDelegate callBackDelegate)
   at System.AppDomain.DoCallBack(CrossAppDomainDelegate callBackDelegate)
   at System.Data.Entity.Migrations.Design.ToolingFacade.Run(BaseRunner runner)
   at System.Data.Entity.Migrations.Design.ToolingFacade.Update(String targetMigration, Boolean force)
   at System.Data.Entity.Migrations.UpdateDatabaseCommand.<>c__DisplayClass2.<.ctor>b__0()
   at System.Data.Entity.Migrations.MigrationsDomainCommand.Execute(Action command)
ClientConnectionId:88b66414-8776-45cd-a211-e81b2711c94b
There is already an object named 'AboutUs' in the database.
PM> 

Написал первый скрипт для MS SQL Server.
Первый раз запустил — отработал нормально.
Теперь вылезает ошибка «There is already an object named … in the database».

Скрипт:

-- начинаем работать в контексте системной базы данных [master]
USE [master]
GO

-- если база данных [dbRBL] уже существует, уничтожаем ее
IF EXISTS (SELECT name FROM sys.databases WHERE name = N'dbRBL')
DROP DATABASE [dbRBL]
GO

-- создаём базу данных [dbRBL]
CREATE DATABASE [dbRBL]
GO

-- переходим в контекст созданной базы данных [dbRBL]
USE [dbSPJ]
GO

-- создаём таблицу читателей [R]
CREATE TABLE [dbo].[R] (
[Rno] [int] IDENTITY(1,1) NOT NULL,
[Rname] [varchar](100) NOT NULL,
[Rsex] [varchar](10) NULL,
[Rbirthday] [date] NULL,
[Rphone] [varchar](30) NULL
)
GO

-- создаём таблицу книг [B]
CREATE TABLE [dbo].[B] (
[Bno] [int] IDENTITY(1,1) NOT NULL,
[Bname] [varchar](100) NOT NULL,
[Bauthor] [varchar](100) NULL,
[Byear] [date] NULL,
[Bpages] [int] NULL,
[Bweight] [int] NULL,
[Bcopies] [int] NULL
)
GO

-- создаём таблицу библиотек [L]
CREATE TABLE [dbo].[L](
[Lno] [int] IDENTITY(1,1) NOT NULL,
[Ladress] [varchar](150) NOT NULL,
[Ldate] [date] NULL,
[Lquantity] [int] NULL,
[Lphone] [varchar](30) NULL
)
GO

-- создаём таблицу записей
CREATE TABLE [dbo].[RBL](
[Rno] [int] NOT NULL,
[Bno] [int] NOT NULL,
[Lno] [int] NOT NULL,
[RBLdate] [date] NULL
)
GO

The there is already an object named in the database fixes error occurs because of already having the same object in the database. If you have changed the namespace or your table is empty, you can also face this error.

You can solve this issue by renaming the new object, updating a database using EF, updating the namespace, etc. Keep reading this article to find all the causes, solutions, and expert recommendations.

Why Am I Getting There Is Already an Object Named in the Database Error?

You are getting there is already an object named in the database because of having the same object in the database, change in the namespace in your project, empty table, or any issue in the migration process, manual modification of the database, running the update-database command multiple times, etc.

Let’s see the leading causes behind the error so that we can find their solutions in the next section.

– The Object Already Exists in the Same Database

One of the leading causes of already an object named in the database is that the database object you are trying to create is already there in the same database, mainly if you are using an SQL server.

You might have accidentally run the same create statement multiple times. This can happen if you are working with multiple scripts or SQL statements that create objects with the same name, and you might be unaware of this because you are not keeping track of the objects you have created.

This can also occur when the AutomaticMigrationsEnabled setting is set to true, resulting in unpredictable migrations and a lack of control over the database structure.

– You Have Changed the Namespace in Your Project

If you have made changes to the namespace of your project, you can face this error. Suppose your database name is myDatabase.__MigrationHistory, which has a column named NamespaceKey.

There the column holds the namespace of your project, and if you change the namespace in your code and if you have not updated the namespace in the NamespaceKey column of the myDatabase.__MigrationHistory table, this error will appear.

– Empty Table

You can encounter this issue if your EFMigrationsHistory table is empty. So when you try to run the update-database, this would have caused the initial migration to be rerun and tables to be recreated, and that’s how the error would have appeared.

The EFMigrationsHistory could be emptied due to an issue with the database or a mistake made while working with the database. Before going for fixing this issue, you must determine the cause of the empty table and take steps to restore the data or modify your database to account for the missing information.

– Migration Process Issue

The cause of this error could be the issue in the migration process; there, you might see the error there is already an object named ” in the database migration. This error occurs when you try to run a database migration in a system that uses an entity framework.

That framework attempts to create a new database object that could be a table, view, or stored procedure and counters an existing object.

This error is similar to the main error discussed in this article.

You can fix the there is already an object named in the database by renaming the new object, updating a database using EF, creating a migration, updating the namespace, Hardcoding the context value, or setting AutomaticMigrationsEnables to false.



There could be a couple of more solutions depending on your case.

– Rename the New Object

If you are getting this error because of having the same object in the same database, you must either rename the new object to a unique name or drop the existing object and recreate it with the desired name.

You can use the DROP statement to delete the existing object and rerun the new object’s creation statement. Make sure to use a unique name for the new object to avoid future conflicts.

– Update a Database Using Entity Framework

To eliminate an object named ” in the database migration or there is already an object named in the database entity framework, you need to update a database using Entity Framework.

For that, you can follow the below steps.

First, you need to add a new migration; you can use the Add-Migration command and then add a name for the migration and the -IgnoreChanges flag. This will create a new migration file that contains the changes you want to make to the database.

After making the necessary changes to the database, you can use the Update-Database command and the -verbose flag to apply the changes from the Initial migration file to the database. The -verbose flag will display additional information about the update process in the console.

You can run these commands from the Package Manager Console, a command-line interface for managing NuGet packages and interacting with Entity Framework.

– Create a Migration

If there is no -IgnoreChanges currently in Entity Framework Core, you can have that by commenting out the code in the up() of the migration file. This will take a snapshot of the current model state, which means that subsequent migrations will only include changes made after the snapshot was taken.

Suppose you have already made some incremental model changes and want to create a baseline migration. In that case, you will need to remove these changes, apply the baseline migration, and then add your changes and create a second migration.

This will allow you to track the changes to your model in a structured way and apply them to the database.

– Update the Namespace

We will suppose the same database name as myDatabase.__MigrationHistory and the column name as NamespaceKey. If you have changed the namespace in your code, It is essential to update the namespace in the NamespaceKey column of the myDatabase._MigrationHistory table.

This confirms that the namespaces in your code and database are consistent, as failing to update the namespace in the database can result as there is already an object named ‘pk_’ in the database error with different namespaces.

For example, if you change the namespace to EFDataAccess in your code, you should update the values of the NamespaceKey column in the myDatabase.__MigrationHistory table to EFDataAccess.Migrations.Configuration.

And then, you can run the update-database command from the Package Manager Console to apply these changes.

– Hardcode the Context Value

You can also use a different approach where you can hardcode the context value in your code to the old namespace value by following these steps:

1. Create a class called YourDbMigrationConfiguration that inherits from DbMigrationsConfiguration<YourDbContext>.
2. In the constructor of this class, assign the old context value to the NamespaceKey property.
3. Create another class called YourDbInitializer that inherits from MigrateDatabaseToLatestVersion<YourDbContext, YourDbMigrationConfiguration>.
4. Leave this class empty.
5. In the static constructor of your DbContext class, call Database.SetInitializer(new YourDbInitializer()).

– Set AutomaticMigrationsEnabled to False

It is recommended to set AutomaticMigrationsEnabled to false and employ coded migrations as an alternative. Doing so will avoid problems with duplicate objects and ensure that each developer on the team uses the same database.

Alternatively, you can combine automatic and scripted migrations if you’re the only developer working on the project and are diligent with your updates. However, it is essential to be careful and not add duplicate objects to the database.

– Add Rows to the EFMigrationsHistory Table

To fix the issue, you can add rows to the EFMigrationsHistory table. Each row represents a migration applied to the database and will include two columns that are MigrationID and ProductVersion.

The MigrationId column contains the name of the migration file, while the ProductVersion column contains the version of EF used to apply the migration.

– Correct Connection String

Ensure that the project you want to run as the main project has the correct connection string in its configuration file. Alternatively, when running the update-database command, you can specify the main project using the StartUpProjectName parameter.

This parameter tells the program which configuration file to use for named connection strings. If you don’t include this parameter, the program will use the configuration file of the specified project.

FAQs

1. Why You Face There Is Already an Object Named in the Database Error?

You can face there is already an object named in the database error while working with any programming language, framework, or IDE that supports database integration. You might see a variation in that error depending on where you are seeing this error.

For example, you can face the below error if you work with visual studio, stored procedures in DBMS like Microsoft SQL server or Oracle, C# programming error, and Django web framework, respectively.

• There is already an object named in the database visual studio.
• There is already an object named in the database stored procedure.
• There is already an object named in the database c#.
• There is already an object named in the database django.

Conclusion

There is already an object named in the database is a common error to occur; however, you now know how to deal with it while avoiding other errors. Let’s see what we learned today:

• You can see this error message if you try to create an object with a name already in use in the database.
• Changing the namespace in your project can also lead you to face this error.
• Renaming the new object or updating the database using EF are two go-to solutions.

We explored some significant issues and their solutions. Now you should be able to find your solutions, and if you ever get confused, you can always get help from this article.