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POCode First Migrations and initialization error
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  1. POCode First Migrations and initialization error
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    copied!<p>I'm unsure about how to use the code first migration feature. In my understanding it should create my database if it's not existing already, and update it to the latest schema according to migration files. But I'm struggling with it, because I always get a lot of errors and I'm unsure overall how to use this properly..</p> <pre><code>internal class Program { private static void Main() { EntityFrameworkProfiler.Initialize(); Database.DefaultConnectionFactory = new SqlCeConnectionFactory("System.Data.SqlServerCe.4.0"); Database.SetInitializer(new MigrateDatabaseToLatestVersion&lt;MyContext, Migrations.Configuration&gt;()); using (var context = new MyContext()) { var exists = context.Database.Exists(); if (!exists) { context.Database.Create(); } var element = context.Dummies.FirstOrDefault(); } } } public class MyContext : DbContext { public MyContext() : base(string.Format(@"DataSource=""{0}""", @"C:\Users\user\Desktop\MyContext.sdf")) { } public DbSet&lt;Dummy&gt; Dummies { get; set; } } internal sealed class Configuration : DbMigrationsConfiguration&lt;MyContext&gt; { public Configuration() { AutomaticMigrationsEnabled = true; } protected override void Seed(CodeFirstTest.MyContext context) { } } </code></pre> <p>Using the Entity Framework Profiler I check what statements are executed. When I run the program with no database existing I get the following output:</p> <blockquote> <p>-- statement #1 SELECT [GroupBy1].[A1] AS [C1] FROM (SELECT COUNT(1) AS [A1] FROM [__MigrationHistory] AS [Extent1]) AS [GroupBy1]</p> <p>-- statement #2 WARN: System.Data.SqlServerCe.SqlCeException (0x80004005): The specified table does not exist. [ __MigrationHistory ] at System.Data.SqlServerCe.SqlCeCommand.ProcessResults(Int32 hr) at System.Data.SqlServerCe.SqlCeCommand.CompileQueryPlan() at System.Data.SqlServerCe.SqlCeCommand.ExecuteCommand(CommandBehavior behavior, String method, ResultSetOptions options) at System.Data.SqlServerCe.SqlCeCommand.ExecuteReader(CommandBehavior behavior) at System.Data.SqlServerCe.SqlCeMultiCommand.ExecuteReader(CommandBehavior behavior) at System.Data.SqlServerCe.SqlCeMultiCommand.ExecuteDbDataReader(CommandBehavior behavior) at HibernatingRhinos.Profiler.Appender.ProfiledDataAccess.ProfiledCommand.ExecuteDbDataReader(CommandBehavior behavior)</p> <p>-- statement #3 SELECT [GroupBy1].[A1] AS [C1] FROM (SELECT COUNT(1) AS [A1] FROM [__MigrationHistory] AS [Extent1]) AS [GroupBy1]</p> <p>-- statement #4 WARN: System.Data.SqlServerCe.SqlCeException (0x80004005): The specified table does not exist. [ __MigrationHistory ] at System.Data.SqlServerCe.SqlCeCommand.ProcessResults(Int32 hr) at System.Data.SqlServerCe.SqlCeCommand.CompileQueryPlan() at System.Data.SqlServerCe.SqlCeCommand.ExecuteCommand(CommandBehavior behavior, String method, ResultSetOptions options) at System.Data.SqlServerCe.SqlCeCommand.ExecuteReader(CommandBehavior behavior) at System.Data.SqlServerCe.SqlCeMultiCommand.ExecuteReader(CommandBehavior behavior) at System.Data.SqlServerCe.SqlCeMultiCommand.ExecuteDbDataReader(CommandBehavior behavior) at HibernatingRhinos.Profiler.Appender.ProfiledDataAccess.ProfiledCommand.ExecuteDbDataReader(CommandBehavior behavior)</p> <p>-- statement #5 SELECT [GroupBy1].[A1] AS [C1] FROM (SELECT COUNT(1) AS [A1] FROM [__MigrationHistory] AS [Extent1]) AS [GroupBy1]</p> <p>-- statement #6 WARN: System.Data.SqlServerCe.SqlCeException (0x80004005): The specified table does not exist. [ __MigrationHistory ] at System.Data.SqlServerCe.SqlCeCommand.ProcessResults(Int32 hr) at System.Data.SqlServerCe.SqlCeCommand.CompileQueryPlan() at System.Data.SqlServerCe.SqlCeCommand.ExecuteCommand(CommandBehavior behavior, String method, ResultSetOptions options) at System.Data.SqlServerCe.SqlCeCommand.ExecuteReader(CommandBehavior behavior) at System.Data.SqlServerCe.SqlCeMultiCommand.ExecuteReader(CommandBehavior behavior) at System.Data.SqlServerCe.SqlCeMultiCommand.ExecuteDbDataReader(CommandBehavior behavior) at HibernatingRhinos.Profiler.Appender.ProfiledDataAccess.ProfiledCommand.ExecuteDbDataReader(CommandBehavior behavior)</p> <p>-- statement #7 SELECT [GroupBy1].[A1] AS [C1] FROM (SELECT COUNT(1) AS [A1] FROM [__MigrationHistory] AS [Extent1]) AS [GroupBy1]</p> <p>-- statement #8 WARN: System.Data.SqlServerCe.SqlCeException (0x80004005): The specified table does not exist. [ __MigrationHistory ] at System.Data.SqlServerCe.SqlCeCommand.ProcessResults(Int32 hr) at System.Data.SqlServerCe.SqlCeCommand.CompileQueryPlan() at System.Data.SqlServerCe.SqlCeCommand.ExecuteCommand(CommandBehavior behavior, String method, ResultSetOptions options) at System.Data.SqlServerCe.SqlCeCommand.ExecuteReader(CommandBehavior behavior) at System.Data.SqlServerCe.SqlCeMultiCommand.ExecuteReader(CommandBehavior behavior) at System.Data.SqlServerCe.SqlCeMultiCommand.ExecuteDbDataReader(CommandBehavior behavior) at HibernatingRhinos.Profiler.Appender.ProfiledDataAccess.ProfiledCommand.ExecuteDbDataReader(CommandBehavior behavior)</p> <p>-- statement #9 begin transaction with isolation level: Serializable</p> <p>-- statement #10 CREATE TABLE [Dummies] ( [Name] nvarchar NOT NULL, CONSTRAINT [PK_Dummies] PRIMARY KEY ([Name]) )</p> <p>-- statement #11 CREATE TABLE [<strong>MigrationHistory] ( [MigrationId] nvarchar NOT NULL, [CreatedOn] [datetime] NOT NULL, [Model] [image] NOT NULL, [ProductVersion] nvarchar NOT NULL, CONSTRAINT [PK</strong>_MigrationHistory] PRIMARY KEY ([MigrationId]) )</p> <p>-- statement #12 INSERT INTO [__MigrationHistory] ([MigrationId], [CreatedOn], [Model], [ProductVersion]) VALUES ('201207261524579_InitialCreate', '2012-07-26T15:24:58.523', 0x1F8B080 , '4.3.1')</p> <p>-- statement #13 commit transaction</p> <p>-- statement #14 SELECT TOP (1) [c].[Name] AS [Name] FROM [Dummies] AS [c]</p> </blockquote> <p>As you can see it is trying to access the database <strong>four</strong> times before it actually creates the database. This does not seem right. When I start the application with an existing database it'll query the database 7 times before any of my actual queries will be executed. Note that this happens with <code>context.Database.Create()</code>, not with <code>.Exists()</code>.</p> <p>Also the seed method of my configuration is never called, but the constructor is.</p> <p>This all just seems very wrong and confusing. I hope someone can enlighten me why the errors happen so often in the beginning, and why my seed method is not called at all.</p> <p>I'm using the latest stable versions of SqlServer compact and Entity Framework.</p> <blockquote> <p>package id="EntityFramework" version="4.3.1" targetFramework="net40"</p> <p>package id="Microsoft.SqlServer.Compact" version="4.0.8854.2" targetFramework="net40"</p> </blockquote>
 

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