实体框架自动迁移多个上下文 [英] Entity Framework Automated Migration multiple context

问题描述

我有两个数据库.当我对一个dbcontext进行更改(添加新的DbSet)时，当运行Web应用程序时，它应该自动将更改应用于正确的数据库.因此，应添加新表.因此，我添加了两个配置类.每个数据库/上下文一个.

I have two databases. When I make a change to one of my dbcontext (adding a new DbSet) it should automatically apply the changes to the correct databases when runnnig my webapplication. So the new table should be added. Therefore I have added two configuration classes. One for each database/context.

但是，使用如下所示的初始化程序，更改始终应用于第二个上下文/数据库.因为这是配置的最新初始化程序.

However using the initializers like below the changes are always applied to the second context/database. Because this is the latest initializer configured.

Database.SetInitializer(new MigrateDatabaseToLatestVersion<DomainReadModelContext, DomainConfiguration>());
Database.SetInitializer(new MigrateDatabaseToLatestVersion<WebsiteReadModelContext, WebsiteConfiguration>());

我也在web.config中尝试过

I also tried it in the web.config

<contexts>
  <context type="Domain.ReadModels.DomainReadModelContext, Domain.ReadModels">
    <databaseInitializer type="System.Data.Entity.MigrateDatabaseToLatestVersion`2[[Domain.ReadModels.DomainReadModelContext, Domain.ReadModels], [Website.Migrations.Domain.DomainConfiguration, Website-WebAppMainModule, Version=1.0.0.0, Culture=neutral]], EntityFramework" />
  </context>
  <context type="Website.ReadModels.WebsiteReadModelContext, Website.ReadModels">
    <databaseInitializer type="System.Data.Entity.MigrateDatabaseToLatestVersion`2[[Website.ReadModels.WebsiteReadModelContext, Website.ReadModels], [Website.Migrations.Website.WebsiteConfiguration, Website-WebAppMainModule, Version=1.0.0.0, Culture=neutral]], EntityFramework" />
  </context>
</contexts

通过程序包管理器应用更改时，它将按应有的方式工作.该表被添加到我的domaincontext数据库中.

When applying the changes via the package manager it works as it should be. The table gets added to my domaincontext database.

Update-Database -config DomainConfiguration

这是因为不支持此操作还是我做错了吗?现在，它似乎仅对最新注册的初始化程序有效.

Is this because this isn't supported or am I doing it wrong? Now it seems to work only for the latest initializer registered.

对于更新，我使用程序包管理器中的添加迁移"命令对迁移"进行了脚手架.

For the update I have scaffolded a Migration using the Add-Migration command in the package manager.

Add-Migration AddUniquePersonReadModelMigration -config DomainConfiguration

这为我产生了以下课程.

This generated following class for me.

public partial class AddUniquePersonReadModelMigration : DbMigration
{
    public override void Up()
    {
        CreateTable(
            "UniquePersonReadModels",
            c => new
                {
                    Id = c.Guid(nullable: false, identity: true),
                    PersonId = c.Guid(nullable: false),
                    DisplayName = c.String(maxLength: 128),
                })
            .PrimaryKey(t => t.Id)
            .Index(p => p.PersonId)
            .Index(p => p.DisplayName, true);
    }

    public override void Down()
    {
        DropIndex("UniquePersonReadModels", new[] { "PersonId" });
        DropIndex("UniquePersonReadModels", new[] { "DisplayName" });
        DropTable("UniquePersonReadModels");
    }
}

所以我的问题是，实体框架是否支持使用初始化程序针对多个上下文进行迁移?如果不是这样，当可以在多个上下文中处理迁移时，这将是一个不错的功能.

So my question is does entity framework support the migrations for multiple contexts using initializers? If not, it would be a nice feature when the migrations can be handled for multiple contexts.

推荐答案

我已通过将迁移"文件夹从我的网站移至单独的程序集来解决了该问题.

I have solved the problem by moving the Migration folder from my website to separate assemblies.

因此而不是以下内容:

Solution/
    DomainReadModels/
        DomainContext.cs
        Classes........
    WebsiteReadModels/
        WebsiteContext.cs
        Classes........
    Website/
        Migration/
            AddSomeTableToDomainMigration.cs
            AddSomeTableToWebsiteMigration.cs
            WebsiteReadModelsConfiguration.cs
            DomainReadModelsConfiguration.cs
        Websitefiles...

我将解决方案更改为:

Solution/
    DomainReadModels/
        Migration/
            DomainReadModelsConfiguration.cs
            AddSomeTableToDomainMigration.cs
        DomainContext.cs
        Classes........
    WebsiteReadModels/
        Migration/
            AddSomeTableToWebsiteMigration.cs
            WebsiteReadModelsConfiguration.cs
        WebsiteContext.cs
        Classes........
    Website/
        Websitefiles...

现在唯一的缺点是我必须在程序包管理器控制台中切换项目...

Now the only disadvantage is I have to switch projects in the package manager console...

这篇关于实体框架自动迁移多个上下文的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！