Add auto-compiled models to What's New

Release notes

The team has been working primarily on EF Core internals, so there are no new big features in EF Core 9 (EF9) Preview 3. However, this means we really need people like you to run your code on these new internals and report back what you find. We want to fix bugs in the new internals as soon as possible in order to have a strong GA release later in the year.

That being said, there are several smaller enhancements included in preview 3. For full details, see What's new in EF Core 9. To discuss the EF9 release, go to Try EF Core 9 now! on GitHub.

Auto-compiled models

Auto-compiled models allow the EF Core compiled model to be automatically regenerated when the model project is built. This means you no longer need to remember to re-run the dotnet ef dbcontext optimize command after your EF model changes. See Auto-compiled models in the What's New docs for more information.

Sugar for `HierarchyId` path generation

First class support for the SQL Server HierarchyId type was added in EF8. In EF9, a sugar method has been added to make it easier to create new child nodes in the tree structure. See Sugar for HierarchyId path generation in the What's New docs for more information.

Everything else in preview 3

Preview 3 contains:

EF Core 9 preview 3 (and Microsoft.Data.Sqlite) contains work from the EF Team at Microsoft (@roji @AndriySvyryd @maumar @ajcvickers @cincuranet @SamMonoRT @luisquintanilla) as well as contributions from the EF Core community. The community PRs in EF9 Preview 3 are:

@lauxjpn: Cleanup duplicate tests (same test ID)
@clement911: Fixed typo in getting-and-building-the-code.md
@Rezakazemi890: 32943-Sugar for HierarchyId path generation
@lauxjpn: Change Where_math(f)_log_new_base queries, so they fail if LOG() parameters are swapped
@SteSinger: 33196 command timeout allow zero

dotnet / EntityFramework.Docs