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POWhat is the correct use of IDatabaseInitializer in EF?
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  1. POWhat is the correct use of IDatabaseInitializer in EF?
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    copied!<p>I have a custom DatabaseInitialiser which is below</p> <pre><code>/// &lt;summary&gt; /// Implements the IDatabaseInitializer to provide a custom database initialisation for the context. /// &lt;/summary&gt; /// &lt;typeparam name="TContext"&gt;TContext is the DbContext&lt;/typeparam&gt; public class ParikshaDataBaseInitializer&lt;TContext&gt; : IDatabaseInitializer&lt;TContext&gt; where TContext : DbContext { /// &lt;summary&gt; /// The method to Initialise the database. /// Takes care of the database cannot be dropped since it is in use problem while dropping and recreating the database. /// &lt;/summary&gt; /// &lt;param name="context"&gt;The DbContext on which to run the initialiser&lt;/param&gt; public void InitializeDatabase(TContext context) { var exists = context.Database.Exists(); try { if (exists &amp;&amp; context.Database.CompatibleWithModel(true)) { // everything is good , we are done return; } if (!exists) { context.Database.Create(); } } catch (Exception) { //Something is wrong , either we could not locate the metadata or the model is not compatible. if (exists) { context.Database.ExecuteSqlCommand("ALTER DATABASE Pariksha SET SINGLE_USER WITH ROLLBACK IMMEDIATE"); context.Database.ExecuteSqlCommand("USE Master DROP DATABASE Pariksha"); context.SaveChanges(); } context.Database.Create(); } } } </code></pre> <p>something about the above code is more than just hacky (Feel free to chip in with help)</p> <p>I then added migrations and got the migration script to work correctly as well.</p> <pre><code> internal sealed class Configuration : DbMigrationsConfiguration&lt;ParikshaContext&gt; { public Configuration() { AutomaticMigrationsEnabled = false; ContextKey = "EFRepository.Context.ParikshaContext"; } protected override void Seed(ParikshaContext context) { } } </code></pre> <p>the migrations work as expected.</p> <p>Now, the questions is in my application startup what should I do ? Something like this </p> <pre><code> var config = new Configuration(); var migrator = new DbMigrator(config); migrator.Update(); </code></pre> <p>and some forums suggested this as well in the constructor which seems a little odd because I don't want to check if the db and schema are correct everytime I use the Context. So, what could be the possible use of this technique or did I get the context of the suggestion as wrong ?</p> <pre><code>public ParikshaContext() : base("Pariksha") { Database.SetInitializer(new ParikshaDataBaseInitializer&lt;ParikshaContext&gt;()); } </code></pre> <p>To summarise, </p> <ol> <li><p>what is the correct use-case for the different techniques available ?</p></li> <li><p>what would be the ideal strategy so that the migrations work in all conditions and when we move databases from one environment to another ?</p></li> </ol>
 

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