Use Entity Framework Code-First Migration to update DB schema when application start

Question

I am developing window application in which DB schema can be different between each release (update view, add/remove column). Therefore I am looking for way to let EF update schema when application start up in client machine. I read some article but they point to package manager command Add-Migration, Update-Database which I can not use in my case. I used repository pattern so when I tried Database.SetInitializer<C>(new MigrateDatabaseToLatestVersion<C, Configuration<C>>()); I got 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. exception But when I set AutomaticMigrationsEnabled = true;I got another error: Table 'TableName' already exists.

I already read and tried above but no success, I updated my question to have more detail @SteveGreene — chinh nguyen van
– chinh nguyen van, Commented Apr 24, 2017 at 14:35
Sounds like you don't have migrations properly configured. You need to make an initial baseline migration Add-Migration MyBaseline -IgnoreChanges. Then you add migrations as normal for subsequent changes. — Steve Greene
– Steve Greene, Commented Apr 24, 2017 at 15:14

chinh nguyen van · Accepted Answer · 2017-05-02 12:27:54Z

I found a workaround, create an extension method

    public static void RunMigration(this DbContext context, DbMigration migration)
    {
        var prop = migration.GetType().GetProperty("Operations", BindingFlags.NonPublic | BindingFlags.Instance);
        if (prop != null)
        {
            IEnumerable<MigrationOperation> operations = prop.GetValue(migration) as IEnumerable<MigrationOperation>;
            var generator = new SqlServerMigrationSqlGenerator();
            var statements = generator.Generate(operations, "2008");
            foreach (MigrationStatement item in statements)
                context.Database.ExecuteSqlCommand(item.Sql);
        }
    }

And then create class MyMigration which inherit DbMigration like normal migration, and when application start, I will check and force it to run like below:

var myMigration = new MyMigration();
myMigration.Up();
this.RunMigration(myMigration);

Collectives™ on Stack Overflow

Use Entity Framework Code-First Migration to update DB schema when application start

1 Answer 1

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related