实体框架6模型优先迁移

本文介绍了实体框架6模型优先迁移的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

所需结果:

将模型优先方法与Entity Framework结合使用，并允许根据模型中的更改自动完成对已部署数据库/模型的更改.自动生成模式差异脚本，以实现平稳的迁移.

Use model first approach with Entity Framework and allow changes to deployed database/ model to be done automatically based on the changes in the model. Automatic schema difference script generation to allow smooth migrations.

是否有一种方法可以在模型优先EF6中执行迁移?我可以看到遍及代码优先的迁移主题，但是在Model First上却没什么.

Is there a way to perform migrations in model first EF6? I can see code first migrations topics all over, but nothing much on Model First.

到目前为止我看到的选项:

Options I saw so far:

• 数据库生成电源包(似乎已过时)
• 以某种方式先转换为代码，然后使用迁移(这并不理想，因为我希望有一个视觉设计师)
• 以某种方式piggy带代码优先迁移( http: //blog.amusedia/2012/08/entity-framework-migration-with-model.html :这是针对EF5，出现了无法在Model First上运行迁移的错误)
• 一些第三方工具?

• Database generation power pack (seems outdated)
• somehow convert to code first, then use migrations (not desirable, as I like to have a visual designer)
• somehow piggy back on code first migrations (blog.amusedia/2012/08/entity-framework-migration-with-model.html : this is for EF5, got error that can't run migrations on Model First)
• some third party tools?

推荐答案

据我所知，仍然没有针对实体框架模型的自动迁移.

As far as I know there still is no automatic migration for Entity framework model first.

我们的方法是:

从模型创建一个新的数据库.

创建一个diff脚本，将旧数据库迁移到新数据库.

验证此差异脚本确实正确. 始终仔细检查自动化工具创建的内容.

我们首先将 Open DB diff 用于我们的模型首次迁移.之后，我们切换到 Redgate的SQL比较，因为它产生了更可靠的迁移. 根据我们的经验，DbDiff产生了许多不必要的SQL，因为它困扰着列的顺序，并且还存在其他一些问题，例如不断删除和重新添加外键.除此之外，它仍然可以很好地完成工作，但是我们必须对其生成的SQL进行很多重复检查.

We first used Open DB diff for our model first migrations. After that we switched to Redgate's SQL compare because it produced more reliable migrations . In our experience DbDiff produced a lot of unnecessary SQL because it bothers with the order that columns are in, and has some other issues like foreign keys constantly being dropped and re-added. Aside from that it still did the job fine, but we had to do a lot of double checking on its generated SQL.