We're using EF Code First and migrations for a project. We're commiting our migrations to source, and everything is great. However, if someone delete's their database, or we get a new person on the project, the database will throw errors because it's trying to run the migrations. Is there a way to make it so that if the database doesn't exist, it ignores migrations? I can't seem to find anything about this.
I would look at how you are using DbMigrationsConfiguration from the Entity framework. You might need something like this in your global asx file:
Database.SetInitializer(new MigrateDatabaseToLatestVersion<YourContext, YourConfiguration>());
Then in your configuration file for migrations you may need something like this:
internal sealed class YourConfiguration : DbMigrationsConfiguration<YourContext>
{
public Configuration()
{
AutomaticMigrationsEnabled = true;
}...
Without more info and code examples, I can only point you in the right direction.
Related
The following used to work. I am unsure what has changed.
var db = new MyDbContext()
var compatible = db.Database.CompatibleWithModel(true)
gives the following error
Model compatibility cannot be checked because the database does not
contain model metadata. Model compatibility can only be checked for
databases created using Code First or Code First Migrations.
I have been able to create and run the migrations using Package Manager and I can see the code in the Migrations folder.
I can see the migrations in the __MigrationHistory table.
I resolved the issue in a different database when the user did not have access to the table. However in this case the user does have access.
The table shows the product version is 6.4.4
I tried creating a new migration to see if there were any differences, but it was empty.
I looked at the configuration.cs in the migrations folder
internal sealed class Configuration : DbMigrationsConfiguration<MigrationDbContext>
{
public Configuration()
{
AutomaticMigrationsEnabled = false;
}
}
Then I corrected the type
var db = new MigrationDbContext()
Then I changed the
I was able to scaffold an existing database using EF Core recently. We want to completely migrate to EF Core, but we've hit some snags and I need your help.
We began by running the scaffold command and ended up with this file structure
C:\>ls .\EFCore
Context
Models
EFCore.csproj
Then after creatinng the Context and the Models, I ran the inital migration command.
dotnet ef migrations add CreateDb
After running that command our directories look like this
C:\>ls .\EFCore
Context
Models
Migrations
EFCore.csproj
C:\>ls .\EFCore\Migrations
20210616210256_CreateDb.cs
20210616210256_CreateDb.Designer.cs
DbContextModelSnapshot.cs
My Problem
The database is already created in all environments, so we don't want entity to execute the inital database migration. Should I delete 20210616210256_CreateDb.cs and 20210616210256_CreateDb.Designer.cs to achieve this?
The other route I can think of is create the __EFMigrationsHistory table and insert a row into it. This would fake that we've already ran the inital db create.
Help please, I would like to do this the cleanest way possible.
Remove/Comment the code inside your Up() and Down() methods of migration file and call update database. You don't want the code which creates table i.e.
CreateTable(
"dbo.YourTable",
c => new
{ //Properties set here })
Your migration class could look like this -
public partial class Initial : DbMigration
{
public override void Up()
{
}
public override void Down()
{
}
}
The current project I am working on, I am telling Entity Framework to do nothing by setting SetInitializer with params null:
public EfDbContext()
{
Database.SetInitializer<EfDbContext>(null); //new NullDatabaseInitializer<EfDbContext>());
}
I have a script that creates a few table. When I running the script, it is creating the dbo.__MigrationHistory in the DB.
How can I disable migration, I thought the above code would disable that.
Am I missing something? I also don't have migration enabled and any configuration files for migration.
I am using EF 6.1.3.
In your migrations folder there is a file called Configuration, in the constructor try something like this:
public Configuration()
{
AutomaticMigrationsEnabled = false;
}
The ugly but easy way to disable the migrations at all regardless the configuration is deleting the table dbo.__MigrationHistory.
I fixed the issue by adding the following code into the Application_Start() in Global.asax:
Database.SetInitializer(new NullDatabaseInitializer<DbContext>());
I have a C# project where I'm using Entity Framework 6.1. I have a few migration files and a Configuration.cs file within the same folder. Configuration.cs contains the following class:
namespace SNS.Database.Migrations
{
public class Configuration : DbMigrationsConfiguration<SNSContext>
{
public Configuration()
{
AutomaticMigrationsEnabled = false;
}
protected override void Seed(SNSContext context)
{
...
}
}
}
If I understand Entity Framework correctly, the Seed method is supposed to be executed after a new database migration file has been applied. Furthermore, to configure this, it's done with the following call:
System.Data.Entity.Database.SetInitializer(new MigrateDatabaseToLatestVersion<SNSContext, Configuration>());
That works fine. However, the Seed method does always get called, even if I haven't made the SetInitializer call.
So my question is, what tells Entity Framework to run Configuration.cs, and why does it always execute the Seed method?
I have already checked in my App.config file, and it doesn't specify codeConfigurationType.
I'm using EF6.0 and implementing my db with SQLServerDatabaseProject.
I want to use the EF Migration tools for Database migration. but since I have my database on DbProject I want all my migration files to be SQLFiles (not c#)
So I would like to know if EF supports this feature and if not, is it possible to write a new Migration class which keeps the EF features but works this way?
Please also consider that I don't want EF to generate my migrations but I would like to be able to use other migration commands such as update-database and ...
==MORE DETAILS ABOUT THE QUESTION==
I don't want to have c# classes load my sql files. The sql files must be saved for up and down migrations directly and be treated exactly as if they are the DbMigration classes.
A simple example of Migrations dir would be something like this:
Migrations
-> up
-> 201510060807125_alter-course-change-family.sql
-> 201510060813136_alter-course-add-mark-column.sql
-> down
-> 201510060807125_alter-course-change-family.sql
-> 201510060813136_alter-course-add-mark-column.sql
Simply in the migration class use SqlFile extension method:
public partial class MyFancyMigration : DbMigration
{
public override void Up()
{
SqlFile("myUpSQLFile.sql");
}
public override void Down()
{
SqlFile("myDownSQLFile.sql");
}
}
Although you can use SqlFile method, I suggest you to write this on Seed method of your Configuration.cs file in your migration folder.
internal sealed class Configuration : DbMigrationConfiguration<YourDbContext>
{
protected override void Seed(YourDbContext context)
{
base.Seed(context);
context.Database.ExecuteSqlCommand(FileReadAllText("migration.sql"));
}
}
If you write migrations in Up method. It will be executed per each migration when you update the database, which I think you don't expect.
What you want is that your scripts run per each Update-Database. (Not per each migration in it)