How to add new table to existing database code first

ef-code-first, entity-framework

Solution

If you have automatic migrations set up this should be pretty straight forward.

If you haven't, you will need to run `Enable-Migrations –EnableAutomaticMigrations` Perhaps do some further reading here first though: http://msdn.microsoft.com/en-gb/data/jj554735.aspx

For anyone looking to update a database with a new table (say I want to add an UserAttachment table to sit alongside my existing User table) using EF code first, do the following:

With automatic migrations enabled you should ensure you have...

1.) Create your new model as you see fit.

2.) Create your Configuration file, something along the lines of:

 class UserAttachmentConfiguration : EntityTypeConfiguration<UserAttachment>
    {
        public UserAttachmentConfiguration()
            : base()
        {
            HasKey(p => p.UserId);
            ToTable("UserAttachment");    

            HasRequired(t => t.User)
                .WithOptional(t => t.UserAttachment);                
        }
    }

3.) Add your `DbSet` and `modelBuilder` data in your main `Context.cs` file

DbSet

public DbSet<UserAttachment> UserAttachment {get; set;}

modelBuilder

modelBuilder.Configurations.Add(new UserAttachmentConfiguration());

4.) Run `update-database` via Visual Studio's `Package Manager Console`, make sure you have selected the correct project from the drop down, this is likely to be a `.Repository` named project.

Your new table should now exist in your database.

Problem

Originally I used EF 6 code first to create a new database and two new tables. The code is: ``` public class TestingContext : DbContext, IDisposable { public DbSet<CallDataRecord> CallDataRecords { get; set; } public DbSet<Attempt> Attempts { get; set; } public TestingContext() : base("Testing") { Database.SetInitializer<TestingContext>(new MigrateDatabaseToLatestVersion<TestingContext, GenericIVR.Migrations.Configuration>()); } protected override void OnModelCreating(DbModelBuilder modelBuilder) { modelBuilder.Entity<Attempt>().HasRequired(t => t.CallDataRecord).WithMany(a => a.Attempts).HasForeignKey(t => t.FKTaskId); modelBuilder.Entity<Attempt>().Property(x => x.AttemptId).HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity).IsRequired(); modelBuilder.Entity<CallDataRecord>().Property(x => x.TaskId).HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity).IsRequired(); } } ``` Now my strategy is changed, I don't want to a new DB. I want to add the new tables to an existing DB, say `DevDB`. How to change the code? DO I have to use `Reverse Engineering Code First?` UPDATED: The connection string is: ``` <connectionStrings> <add name="Testing" connectionString="Data Source=dddd.corporate.xxxx.com; Initial Catalog=Testing; User ID=sa; Password=password; MultipleActiveResultSets=True" providerName="System.Data.SqlClient" /> ```

Original source