How do you update an edmx file with database changes?

Question

I have an edmx file and I changed a table in my database. I know that there is an "Update Model from database" wizard, however in many cases this is useless.

For example if I change a field from non null to nullable or if I remove fields the update model does not reflect the changes. I have had to remove the entity and add it back in to get the changes to appear in my model.

Per the following question: How do I propagate database changes to my .edmx file?

One of the answers seems to say the same thing, that you need to remove the entity and add it back in.

Is this the definitive answer or is there a better way to do this?

Answer 1

Updating an EDMX the safe way:

As you have found, the update from database does not always change existing properties correctly.

From our day-to-day use of EDMX updating (100s of updates over 24 months), I would recommend the following sequence for updating an EDMX.

Delete existing model and then update:

1. Open the EDMX designer
2. Ctrl-A to select all
3. Delete key to delete all models in the designer
4. IMPORTANT: Do not save the EDMX at this point if you are using TFS for source control!*
5. Now right-click and select "Update Model from Database" to recreate the entire model again.
6. Rebuild project to propagate changes

This will obviously lose any manual tweaks you have made to the model, but manual tweaks are to be avoided if possible. This makes the entire process reproducible at any time (which is a good thing).

Important notes:

• If you have auto-save turned on in Visual Studio, you need to select the update (step 5 above), quickly to avoid an auto-save saving everything.
• If you are using TFS for source control, and happen to save the EDMX after emptying it, TFS will mark all the generated files as "deleted" and updating the EDMX again can result in disconnected files that are not in source control!.
• This process will not update any stored procedures. Further, I have found that a refresh of an EDMX will also not update stored procedures where just the return type has changed (still current as of EF 6.1.1).

Additional Recommendation:

Keep your EDMX in a separate library. This also becomes a great place to add additional TT files and partial classes (e.g. to extend function of EDMX models). I also place any extension methods for the database context in this library. The migration files get generated in the library too keeping it all nicely contained.

Update April 2015

The latest Release 4 of Visual Studio 2013 appears to have resolved a lot of the TFS issues. We now see Visual Studio checkout generated files, then revert them if they are unchanged. The above steps still appear to be the safest approach.

Update September 2015

Using latest VS2013 Release 5, we still have issues if a save occurs during EDMX update. You can still wind up in a state where pending deletes causes your tt files to be removed from source control during the update. The secret is to update fast between steps 4 and 5! :)