I have a situation where I need to make changes to my Model (code-first) and mirror the changes manually on the database. Migrations are not an option. Unfortunately, this causes entity framework to throw an exception when it validates the schema against the model (using the __MigrationHistory table). Is there a way to disable the schema validation that entity framework does? I'm using EF 4.3 specifically.
I would imagine you could create your own implementation of IDatabaseInitializer that does nothing, and use Database.SetInitializer().
Related
I have a old DB that I need to create a new module for which will include some new tables.
The DB currently has no Entity Framework so I want to just add my new tables and just work with them and ignore the previous ones.
This post says in previous versions of entity framework you just need to do this:
add-migration Initial -IgnoreChanges
but EF Core does not support "Ignore Changes" as explained here.
I cannot find an alternative in Entity Framework Core.
How do I add my migrations for my specific tables whilst ignoring the rest of the existing database?
I have project with code first migrations. And I was stuck in situation, when Add-Migration throws an Exception. So I decided to use it with -IgnoreChanges and write migration code myself.
Now I want to check whether the database after the custom migration is compatible with the model. All I found is CompatibleWithModel method, but it compares the model with the schema stored in the __MigrationHistory table, and not with the schema of the database itself, so in my case it is useless.
EF 6.1.3
I'm trying to generate an entity from my SQL database using the ADO.NET Entity Data Model using the ADO.NET DbContext Generator. When I generate my edmx from the database I can see it in the model. I right click on my tt file (which is in a separate project) and run the custom tool. The entity appears. It's called CustomerContact. However, my dbcontext does not have a CustomerContacts collection. What is going on here?
I figured it out. The problem was the different versions of Entity Framework. I updated both projects to the latest version of EF and it works now
I'm using an existing database and I have mapped one of the tables as an entity (as i needed to map a foreign key).
So when it comes to initialising this database I would like EF to ignore this entity since it already exists.
How would I go about doing this?
You should create an empty migration as the first migration with the -IgnoreChanges flag to allow Entity Framework to get a snapshot of the existing database.
So out of the gate use:
Add-Migration InitialMigration -IgnoreChanges
and that will create a blank migration but it will update the Entity Framework metadata allowing the existing tables to exist and not be touched by migrations.
Also to be mentioned that the naming conventions that Entity Framework expects and your database schema may differ. You may need to manually setup the foreign keys using the Fluent API.
I didnt check with EF 6 specifically, but I think default EF behavious is that when the database exists, then it presume all model be ready and therefore will create no tables. If you want your initialization code to create tables with code first, use initialization code for prepare data. Look here :
http://www.entityframeworktutorial.net/code-first/seed-database-in-code-first.aspx
I'm migrating my project from database-first to code-first.
Entity Framework does some nice work creating my new database (that should mimic the old one).
I'm using a combination of data annotations and the fluent API to describe my tables.
My database has a few indexes and I would like Entity Framework to create them as well. It seems the old way to do this is to define your own Initializer and use custom T-SQL.
But now that we have EF Migrations it should be easier to do so.
I can't seem to figure out how to combine CreateDatabaseIfNotExists<> with an automatic migration to create the indexes. I've tried to use the MigrateDatabaseToLatestVersion<,> but it doesn't seem to perform the migration after the Database has been created.
What is the proper way to create indexes and constraints on database creation now that we have Entity Framework 4.3?
Don't use CreateDatabaseIfNotExists if you want to use migrations. Use MigrateDatabaseToLatestVersion from the beginning - it will create your database as well. Put your index creation code (calls to CreateIndex) into Up method of your migration class.
If you already have existing database and you want to use migrations you must first create initial migration.