core/release-notes/10.0/preview/preview5/efcore.md

Entity Framework Core 10 Preview 5 - Release Notes

Here's a summary of what's new in Entity Framework Core in this preview release:

• Custom Default Constraint Names

Entity Framework Core 10 updates:

• What's new in Entity Framework Core 10 documentation
• Breaking change in Entity Framework Core 10

Custom Default Constraint Names

In previous versions of EF Core, when you specified a default value for a property, EF Core would always let the database automatically generate a constraint name. Now, you can explicitly specify the name for default value constraints for SQL Server, giving you more control over your database schema.

You can now specify a constraint name when defining default values in your model configuration:

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.Entity<Blog>()
        .Property(b => b.IsActive)
        .HasDefaultValue(true, "DF_Blog_IsActive");

    modelBuilder.Entity<Post>()
        .Property(p => b.CreatedDate)
        .HasDefaultValueSql("GETDATE()", "DF_Post_CreatedDate");
}

You can also call UseNamedDefaultConstraints to enable automatic naming of all the default constraints. Note that if you have existing migrations then the next migration you add will rename every single default constraint in your model.

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder
        .UseNamedDefaultConstraints();
}