更改asp.net mvc模型的EF Code First模型后，如何在Azure中正确更新SQL数据库？

Question

It seems like I always have a variety of problems doing this, and usually I end up nuking the db out of frustration and rebuilding, but obviously there has to be some way to do this.

I have an existing asp.net mvc web app living with its sql db in azure. Works fine has some data that can be replaced but, again, the point is to learn how to update model without destroying the database.

In VS2017 I add one property public string ScreenShot { get; set; } public string ScreenShot { get; set; }

I make some small changes to my mvc and web api controllers to handle this extra property. I update my localdb via packmanager console and add-migration addprop and update-database . Works fine, run it locally, no probs.

Goto publish, goto settings, check update database. Click publish. It hangs for like 5 or 6 min and I get:

Warning : A project which specifies SQL Server 2016 as the target platform may experience compatibility issues with Microsoft Azure SQL Database v12. when publishing

I try publishing several times and get the same thing. Google, look around, scratch my head, try again and it seems to publish. Site opens, and somehow I have lost my bootstrap theme. In fact in my Content folder I now have 4 files i believe are new: bootstrap-theme. (css,css.map, min.css, min.css.map) bootstrap-theme. (css,css.map, min.css, min.css.map) (same prefix , different suffix) as well as what I think are virgin versions of those without theme in the name, and seems to be the default mvc theme of black and white. When I goto my app and I get an generic error and checking elmah I get:

System.InvalidOperationException: The model backing the 'TaskTrackerContext' context has changed since the database was created. Consider using Code First Migrations to update the database ( http://go.microsoft.com/fwlink/ ? LinkId=238269).

Well I really thought thats what I did. Almost forgot one thing! Maybe this is where my problem lies: I actually had to run two migrations-in addition to the model change I dropped a column that had never been used (scaffolding a controller for a DTO version of one of my models added it to my context which created a table).

I did create a new branch before making any of these change so I could just revert back but at some point I have to make this work and have to understand how to do it without destroying my db and remaking fresh. A check in SQL object explorer shows it added the ScreenShot column to my table but didn't remove the unused table.

Answer 1

This works for me : In visual Studio, go to publish settings and then select the option

Execute Code First Migration

Please see the screenshots below

Kind regards