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POMethod with generic type using runtime type
 

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  1. POMethod with generic type using runtime type
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    <p>I'm trying to migrate a database with entity framework at runtime.<br> This is how you would usually do so:</p> <pre><code>Database.SetInitializer&lt;TContext&gt;(new MigrateDatabaseToLatestVersion&lt;TContext,TMigrationsConfiguration&gt;); } </code></pre> <p>However I do not know TContext or TMigrationsConfiguration until runtime.</p> <p>How would I execute this method with runtime types?</p> <hr> <p><em><strong>Update 1</em></strong></p> <p>@Alexander Balte's suggestion put me onto using the interface IDatabaseInitializer</p> <p>So this compiles without error:</p> <pre><code>foreach (IDatabaseInitializer&lt;DbContext&gt; initializer in moduleNeedingMigration.initializers) { System.Data.Entity.Database.SetInitializer(initializer); } </code></pre> <p>However i cannot do this:</p> <pre><code>public IEnumerable&lt;IDatabaseInitializer&lt;DbContext&gt;&gt; initializers { get { List&lt;IDatabaseInitializer&lt;Module1Context&gt;&gt; list = new List&lt;IDatabaseInitializer&lt;Module1Context&gt;&gt;(); MigrateDatabaseToLatestVersion&lt;Module1Context, Configuration&gt; init = new MigrateDatabaseToLatestVersion&lt;Module1Context, Configuration&gt;(); list.Add(init); return list;//Error cannot convert type List&lt;IDatabaseInitializer&lt;Module1Context&gt;&gt; to IEnumerable&lt;IDatabaseInitializer&lt;DbContext&gt;&gt; } } </code></pre> <p><strong>Note</strong> that Module1Context inherits DbContext</p> <hr> <p><em><strong>Update 2</em></strong></p> <p>This compiled:</p> <pre><code>return list.Cast&lt;IDatabaseInitializer&lt;UpfContext&gt;&gt;(); </code></pre> <p>However when i run the application I got this error:</p> <pre><code>System.Data.Entity.MigrateDatabaseToLatestVersion`2[Module1.Models.Module1Context,Module1.Migrations.Configuration]' to type 'System.Data.Entity.IDatabaseInitializer`1[System.Data.Entity.DbContext]'. </code></pre>
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    1. USMrJD
    1. USMrJD
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    1. CODo you have a variable like `Type T` or it's inside a generic class `class Blah<T>`?
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      1. POMethod with generic type using runtime type
      1. USAlvin Wong
    2. COI have a variable at runtime
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    3. COIt is impossible to cast `IDatabaseInitializer<Module1Context>` to `IDatabaseInitializer<DbContext>` because `IDatabaseInitializer` is contravariant.
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      1. POMethod with generic type using runtime type
      1. USAlexander Balte
 

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