实体框架代码优先种子数据库 [英] Entity Framework Code First Seed database

问题描述

我将E.F.与Code First方法结合使用...现在我必须在数据库中填充一些数据...但是我却不容易做到...其他内容尚不清楚... 我已经在Google上搜索过，但是找到的每个解决方案都假设我必须创建一个自定义的初始化...，但是我不想创建一个自定义的初始化..

I am using E.F. with Code First approach... Now I have to fill the database with some data... but I cannot do it easily... Simething is not clear... I have googled but every solution I have found suppose I must create a custom Initilization... but I do not want to create a custom Initialization..

每当我启动一些测试时，我需要的是一种方法删除数据库，重新创建它，并用一些数据填充它.

What I need is a method the everytime I launch some tests DROP the database, RE-CREATE it and fill it with some data.

我试图做的是:

public PublicAreaContext()
    : base("PublicAreaContext")
{
    Database.SetInitializer<PublicAreaContext>(new DropCreateDatabaseAlways<PublicAreaContext>());
}

然后，我尝试在Configuration类中强制使用Seed方法.因此:

Then I have tried to impement the Seed method inside the Configuration class. So:

internal sealed class Configuration : DbMigrationsConfiguration<PublicAreaContext>
{
    protected override void Seed(PublicAreaContext context)
    {
        ...
    }
}

但是当我尝试调试时，我从未进入种子方法...我进入了Configuration类的构造函数，但没有进入种子...为什么?

But when I try to debug I never go in the seed method... I go in constructor of the Configuration class, but not in the seed... why?

感谢您的帮助

推荐答案

您在混淆种子方法.创建数据库时可以使用一种初始化程序，而移植时可以使用一种初始化程序.参见 http://blog.oneunicorn.com/2013/05/28/database-initializer-and-migrations-seed-methods/

You are confusing seed methods. There is one for initializers that you can use when your database is created and there is one for migrations. See http://blog.oneunicorn.com/2013/05/28/database-initializer-and-migrations-seed-methods/

由于您一直在使用DropCreateDatabaseAlways，因此迁移将不会运行，因此请执行以下操作:

Since you are using DropCreateDatabaseAlways, migrations won't run, so do something like this:

public static class MyDatabase
{
    public static void Initialize()
    {
        Database.SetInitializer(new MyInitializer());
    }
}

public class MyInitializer : DropCreateDatabaseAlways<PublicAreaContext>
{
    protected override void Seed(PublicAreaContext context)
    {
        base.Seed(context);
        context.Roles.Add(new Role
        {
            ID = 1,
            Name = "User",
        });
        context.Roles.Add(new Role
        {
            ID = 2,
            Name = "Admin",
        });
        context.SaveChanges();
    }
}

其他示例: http://www.codeguru.com/csharp/article.php/c19999/Understanding-Database-Initializers-in-Entity-Framework-Code-First.htm

http://www.techbubbles.com/aspnet/seeding-a-database-in-entity-framework/

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