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POEntity Framework 4.3.1 add-migration error: "model backing the context has changed"
 

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  1. POEntity Framework 4.3.1 add-migration error: "model backing the context has changed"
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    <p>I'm getting an error when trying to run the EF 4.3.1 add-migrations command:</p> <p>"The model backing the ... context has changed since the database was created". </p> <p>Here's one sequence that gets the error (although I've tried probably a dozen variants which also all fail)...</p> <p>1) Start with a database that was created by EF Code First (ie, already contains a _MigrationHistory table with only the InitialCreate row).</p> <p>2) The app's code data model and database are in-sync at this point (the database was created by CF when the app was started).</p> <p>3) Because I have four DBContexts in my "Services" project, I didn't run 'enable-migrations' command (it doesn't handle multipe contexts). Instead, I manually created the Migrations folder in the Services project and the Configuration.cs file (included at end of this post). [I think I read this in a post somewhere] </p> <p>4) With the database not yet changed, and the app stopped, I use the VS EDM editor to make a trivial change to my data model (add one property to an existing entity), and have it generate the new classes (but not modify the database, obviously). I then rebuild the solution and all looks OK (but don't delete the database or restart the app, of course).</p> <p>5) I run the following PMC command (where "App" is the name of one of the classes in Configuration.cs):</p> <p>PM> add-migration App_AddTrivial -conf App -project Services -startup Services -verbose</p> <p>... which fails with the "The model ... has changed. Consider using Code First Migrations..." error.</p> <p>What am I doing wrong? And does anyone else see the irony in the tool telling me to use what I'm already trying to use ;-)</p> <p>What are the correct steps for setting-up a solution starting with a database that was created by EF CF? I've seen posts saying to run an initial migration with -ignorechanges, but I've tried that and it doesn't help. Actually, I've spent all DAY testing various permutations, and nothing works!</p> <p>I must be doing something really stupid, but I don't know what!</p> <p>Thanks,</p> <p>DadCat</p> <p>Configuration.cs:</p> <p>namespace mynamespace { internal sealed class App : DbMigrationsConfiguration { public App() { AutomaticMigrationsEnabled = false; MigrationsNamespace = "Services.App.Repository.Migrations"; }</p> <pre><code> protected override void Seed(.Services.App.Repository.ModelContainer context) { } } internal sealed class Catalog : DbMigrationsConfiguration&lt;Services.Catalog.Repository.ModelContainer&gt; { public Catalog() { AutomaticMigrationsEnabled = false; MigrationsNamespace = "Services.Catalog.Repository.Migrations"; } protected override void Seed(Services.Catalog.Repository.ModelContainer context) { } } internal sealed class Portfolio : DbMigrationsConfiguration&lt;Services.PortfolioManagement.Repository.ModelContainer&gt; { public Portfolio() { AutomaticMigrationsEnabled = false; MigrationsNamespace = "Services.PortfolioManagement.Repository.Migrations"; } protected override void Seed(Services.PortfolioManagement.Repository.ModelContainer context) { } } internal sealed class Scheduler : DbMigrationsConfiguration&lt;.Services.Scheduler.Repository.ModelContainer&gt; { public Scheduler() { AutomaticMigrationsEnabled = false; MigrationsNamespace = "Services.Scheduler.Repository.Migrations"; } protected override void Seed(Services.Scheduler.Repository.ModelContainer context) { } } </code></pre> <p>}</p>
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    1. USLadislav Mrnka
    1. USDadCat
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    1. COWhat exactly are you trying to achieve? EF migrations don't support handling of multiple contexts to single database - avoiding running `Enable-Migrations` doesn't change it. Also creating classes through EDM designer is not a code first.
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      1. POEntity Framework 4.3.1 add-migration error: "model backing the context has changed"
      1. USLadislav Mrnka
 

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