I have been using Entity Framework (5.0) for a while now in a project (ASP.NET MVC in VS2012 Express). Right now, though, I am no longer able to add migrations.
PM > Add-Migration -projectName MyProject.DAL TestMigration
Unable to update database to match the current model because there are pending changes and automatic migration is disabled. Either write the pending model changes to a code-based migration or enable automatic migration. Set DbMigrationsConfiguration.AutomaticMigrationsEnabled to true to enable automatic migration.
I do not know if this gives any clue but the 'Unable to ..." text is displayed in red.
I have tried to enable automatic migration (which makes no sense as I am trying to write the pending model changes to a code-based migration) and that results in the required migration in the database. However this is not what I want because I then I do not have a migration in the project.
I have tried to remove the database and recreate the database. The database is recreated (up to the previous migration) but when I then try to use the Add-Migration I still get the "Unable to update.." error.
Edit
I tried the -force parameter but with no difference.
The contents of my configuration class (I did not change anything after the previous migration):
public Configuration()
{
AutomaticMigrationsEnabled = false;
}
protected override void Seed(Bekosense.DAL.Context.BekosenseContext context)
{
context.Database.ExecuteSqlCommand(Properties.Resources.TriggerAlertMessageDrop);
context.Database.ExecuteSqlCommand(Properties.Resources.TriggerAlertMessageCreate);
context.Database.ExecuteSqlCommand(Properties.Resources.TriggerAlertMessageSentDrop);
context.Database.ExecuteSqlCommand(Properties.Resources.TriggerAlertMessageSentCreate);
context.Database.ExecuteSqlCommand(Properties.Resources.AddDbUsers);
}
Edit 2
I found out that I am able to do an add-migration when I comment the following line out in my DbContext:
//Database.SetInitializer(new MigrateDatabaseToLatestVersion<MyContext, Configuration>());
when I leave the line above active and comment out everything in the Configuration file, it still won't work.
Why is the Database.SetInitializer line causing this strange behaviour?
You can reset the entity framework to solve your problem [But keep it mind it will bring the Migration to the default state]
Note: To take a backup before performing the following
You need to delete the present state:
Delete the migrations folder in your project
Delete the __MigrationHistory table in your database (may be under system tables)
You will find the __MigrationHistory table in your database [Under App_Data Folder]
Then run the following command in the Package Manager Console:
Enable-Migrations -EnableAutomaticMigrations -Force
Use with or without -EnableAutomaticMigrations
And finally, you can run:
Add-Migration Initial
This may also help you
Never use automigrations, that gave me problems in the past (when migrating the database down, use the correct way to do it from the start!)
This line should be in your global.asax:
Database.SetInitializer(new MigrateDatabaseToLatestVersion<MyContext, Configuration>());
And not in your DbContext!
Other tips if the above won't help:
Perhaps you have multiple layers in your application:
Add-Migration 000 -StartupProjectName "NameOfTheProjectInSolutionExplorer" -ConfigurationTypeName "MyConfiguration" -ConnectionString "theconnectionstring;" -ConnectionProviderName "System.Data.SqlClient" -Verbose
Above is the Add-Migration command i use for a multi-layered application.
Same thing for an update of the database
Update-Database -ConfigurationTypeName "SlaveConfiguration" -StartupProjectName "FacturatieMVCv2.Data" -Verbose -script
In my case I've got the same error because I was forcing ObjectContext.CommandTimeout on class DbContext at constructor method during migration.
Try removing it
((IObjectContextAdapter)this).ObjectContext.CommandTimeout = 5000;
This worked for me:
update-database -targetmigration:"0" -force -verbose
add-migration Initial
update-database
Related
I am trying to perform a consolidation or merge of migrations on one of many DBContexts.
We have a .NET 6 solution which utilizes several databases. All db contexts have been defined in a single project, in separate folders. I.e.
Solution\
- Business_Logic_Project_1\
- Business_Logic_Project_2\
- Business_Logic_Project_3\
- Database_Project\
- Context1\
- Migrations\
- Models\
- Context1.cs
- Context2\
- Migrations\
- Models\
- Context2.cs
- Context3\
- Migrations\
- Models\
- Context3.cs
- Database_Project.csproj
- Startup_Project
- Startup_Project.csproj
- Solution.sln
I do the following:
I open a command prompt and go to the root of the solution.
I then delete all migrations in the Database_Project\Context2\Migrations.
I then execute this command:
dotnet ef migrations add <<MIGRATION_NAME>> --context Context2 --project Database_Project --startup-project Startup_Project --output-dir Context2\Migrations
I empty the __EFMigrationsHistory table in the database.
Finally, I run this command to finish the consolidation:
dotnet ef database update <<MIGRATION_NAME>> --context Context2 --project Database_Project --startup-project Startup_Project
This fails with the error message: The migration '<<MIGRATION_NAME>>' was not found.
So, I think this is because the migrations are placed under the context folders, and the database update command do not look that deep. There doesn't appear to be a way of telling the command where to look for migrations though, so what to do?
Hard to pinpoint the exact reason but, while providing the migration name in update command, did you include the .cs extension? If so, please try without that.
Other possibilities include
some typo in the command
missing migration designer files
Well, I figured it out, but I forgot about this question, so I can't remember the issue and how I solved it.
However, I found that these steps works:
Step 1: Delete all *.cs files under the Migrations folder. Except the *ModelSnapshot.cs.
Step 2: Copy all records from the __EFMigrationHistory to the __EFMigrationHistoryBackup:
INSERT INTO dbo.[__EFMigrationHistoryBackup] (MigrationId, ProductVersion)
SELECT MigrationId, ProductVersion FROM dbo.[__EFMigrationsHistory]
Step 3: Empty the __EFMigrationHistory table:
DELETE FROM dbo.[__EFMigrationHistory]
Step 4: Create a new migration like: dotnet ef migrations add Migration_Merge_2022Q4.
Both the Up() and Down() methods of the migration should be empty. If not, comment out all code inside the two methods.
Step 5: Update the database like: dotnet ef database update. This should add a new record in the __EFMigrationHistory table, but since Up() and Down() is empty, no changes is made to the database.
Step 6: Uncomment the Up() and Down() methods.
Step 7: Check the changes into Git.
I have tried to scaffold two views from a database in a SQL Server. Code in .Net 5.0.
Scaffold-DbContext "conn-string"
Microsoft.EntityFrameworkCore.SqlServer
-OutputDir Entities -ContextDir .
-Context MyContext -UseDatabaseNames -Force
-NoPluralize -NoOnConfiguring -Tables View1,View2
This runs without error but no entities for this views are generated and I get a message:
Unable to find a table in the database matching the selected table 'View1'.
Unable to find a table in the database matching the selected table 'View2'.
How do I use Scaffold-DbContext to get these two views?
Aside from referencing the db schema, you could be stuck with this error because the actual project itself does not compile.
I commented out all the code associated to the DbContext model, and ran the following equivalent Scaffold command.
Scaffold-DbContext "Server=MyServer;Database=myDb;user=theUser;password=thePwd;" Microsoft.EntityFrameworkCore.SqlServer -OutputDir Entities -ContextDir . -Context MyContext -UseDatabaseNames -Force -NoPluralize -NoOnConfiguring -Tables <<your database view>>
The command ran successfully and created my class in the root folder. I then moved it into my Models folder and went from there. That is optional of course.
There is more info here as to why you need to make sure the solution compiles before you run the scaffold command.
I have some data in my database in a table called "Test".
I've made a duplicate of that table called "CopyTest".
If i change:
modelBuilder.Entity<IISLog>()
.ToTable("Test");
to:
modelBuilder.Entity<IISLog>()
.ToTable("CopyTest");
I get an error saying:
context has changed since the database was created. Consider using
Code First Migrations to update the database
How can i stop this from showing? It's just a table name change :)
Solution 1:
Delete First Migration and than try:
Add-Migration <migration-name>
Then open Migration file and change Table Name Manually. After that:
update-database -verbose
If it not works.
Solution 2:
Try to delete Migration History from SQL server Management studio .
Reference URL - Resetting Entity Framework Migrations to a clean Slate
Migrate to the initial DB
with
Update-Database -TargetMigration:"name_of_migration"
then update to your current state:
Update-Database
if necessary add your migration again:
Add-Migration TableNameUpdate
Add a new migration using add-migration Rename_Test_To_CopyTest
Then, in the resulting file, use the RenameTable method:
public partial class Rename_Test_To_CopyTest : DbMigration
{
public override void Up()
{
RenameTable("dbo.Test", "dbo.CopyTest");
}
public override void Down()
{
RenameTable("dbo.CopyTest", "dbo.Test");
}
}
Then use update-database as usual.
In my solution, I have a Data project that contains multiple Entity Framework 6.1.3 migration configuration classes. My goal is to run Entity Framework migration steps - for one of them, against an existing database - from TeamCity (or, to simplify, from a command line).
The migration configuration class I am using is the following:
namespace MyProject.Data
{
public partial class MyCustomMigrationConfiguration :
DbMigrationsConfiguration<MyCustomContext>
{
public MyCustomMigrationConfiguration()
{
AutomaticMigrationsEnabled = false;
AutomaticMigrationDataLossAllowed = true;
MigrationsDirectory = #"Migrations\MyCustomContext\MigrationSteps";
}
}
}
I can successfully run the following command from Package Manager Console in Visual Studio:
Update-Database -Verbose -StartUpProject Web -ConnectionString '-my
connection string here-' -ConfigurationTypeName
MyCustomMigrationConfiguration -ConnectionProviderName
'System.Data.SqlClient'
I want to do the same thing from a command line, so I run this:
migrate.exe MyProject.Data.dll "MyCustomMigrationConfiguration"
/startUpConfigurationFile=MyProject.Web.dll.config
/connectionString="-my connection string here-;"
/connectionProviderName="System.Data.SqlClient" /verbose
However, I get the following error:
ERROR: The migrations configuration type
MyCustomMigrationConfiguration was not be found in the assembly
‘MyProject.Data'.
Any suggestions on how to fix this, please?
You can specify the directory where are all the dependencies (assemblies) needed to run your code. You can do that by using the /startUpDirectory option, as explained here:
Specify working directory
Migrate.exe MyApp.exe /startupConfigurationFile=”MyApp.exe.config” /startupDirectory=”c:\MyApp”
If you assembly has dependencies or reads files relative to the working directory then you will need to set startupDirectory.
Found the solution (I ended up downloading the Entity Framework source code from http://entityframework.codeplex.com/ and debugging the migrate console application).
Apparently, all the dependencies of MyProject.Data.dll need to be copied in the same folder with it and migrate.exe, otherwise the Entity Framework migrate.exe tool will throw the misleading error message above.
Entity Framework could really use better error handling and a clearer error message in this case.
As a reference to Entity Framework devs: the following code in TypeFinder.cs was returning a null type because the dependencies of MyProject.Data.dll were not copied in the folder of migrate.exe:
type = _assembly.GetType(typeName, false);
We're using EF 5RC, code first with migrations. I feel like this should be an easy question to answer (i hope). Is there a good way to figure out what the automatic migration is attempting to do.
I've added a migration through the Add-Migration PS command.
I've invoked Update-Database and all seems fine with that migration.
Now - I'm just running Update-Database like i normally do, but with the following error:
PM> update-database -Verbose
Using StartUp project 'Web'.
Using NuGet project 'DataAccess'.
Specify the '-Verbose' flag to view the SQL statements being applied to the target database.
Target database is: 'UserGroup' (DataSource: (localdb)\v11.0, Provider: System.Data.SqlClient, Origin: Configuration).
No pending code-based migrations.
Applying automatic migration: 201206301526422_AutomaticMigration.
Automatic migration was not applied because it would result in data loss.
Notice, i'm adding the -Verbose option, and I've tried it again with the -Script. But I have no idea what we're migrating to; and what SQL - or what it thinks will result in data loss.
I do not want to simply enable "allow data loss" here, but am trying to understand how to troubleshoot these migrations.
Thank you in advance!
Just run:
PM> Update-Database -Script -Force
This will generate the SQL and display it in a window without running it.
I got this error on Azure after a publish , but there u cant use -Force , so global solution (and no need for -Force on local too )
public Configuration()
{
AutomaticMigrationsEnabled = true;
AutomaticMigrationDataLossAllowed = true; // <-- THIS LINE
}