EF 7 Migration to Existing Database

entity-framework-core entity-framework-migrations asp.net5
user6067295 picture user6067295 · Apr 20, 2016 · Viewed 8k times · Source

I am working on a web project using ASP.Net 5 and EF7.

I have imported all the tables from existing database onto my models in my project. However, I am having problems in regards with migrations.

I have created the initial migration, made some changes on particular entity, create another migration following the changes I have made and now want to apply the changes on the database.

After running this command below:

dnx ef database update [Migration]

the dnx is trying to apply the 'initial' migration with all the entities which are already in database and this causes an error as below:

{ There is already an object named ['EntityName'] in the database. }

Can you please advise on how to do the migration on the existing database?

Thanks Saeed

Answer

Steve Greene picture Steve Greene · Apr 20, 2016

In EF6 you would run a migration with the -IgnoreChanges flag and it would take a snapshot of the model without any Up() code. This is missing from EF 7(EF Core) as indicated here.

The workaround for now is delete or comment out the code for existing database objects from the Up() code of the migration and then update-database. Subsequent migrations will then include only the changes.

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