实体框架：多个数据库具有相同的架构 [英] Entity Framework: multiple DB having the same schema

问题描述

我刚刚创建了一个ASP.NET MVC 4安培;项目的WebAPI。从那以后，我已经添加了的.edmx 数据源项目。

I have just created an ASP.NET MVC 4 & WebAPI project. After that I have added .edmx data source to project.

我有相同的架构多个数据库。动态我想用在EF提供默认的构造函数来替换连接字符串。

I have multiple databases with the same schema. Dynamically I want to replace connection string using default constructor provided in EF.

但 Model1.Designer.cs ，每次我得到错误，如时间与相同签名成员已经声明。

But in Model1.Designer.cs, every time I get error like "Member with same signature already declared".

我无法解决这个问题。

I'm unable to solve this problem.

推荐答案

是的，它的作品！你只需要改变的是连接字符串。

Yes, it works! All you need to change is the connection string.

和我刚才测试了它为了满足自己的好奇心。

And I have just tested it in order to satisfy my own curiosity.

下面是我采取的步骤：结果
1.将现有的数据库和创建一个模型它。结果
2.创建一个新的空数据库。结果
3.在 SQL Management Studio中右键单击第一个数据库 - >任务 - > 导出数据。所有IT的数据导出到新创建的数据库。结果
4.从第二个数据库中删除一些记录。结果
5.写这个code：

Here are the steps that I took:
1. Take an existing database and create a model for it.
2. Create a new empty database.
3. In SQL Management Studio right click the first database -> Tasks -> Export Data. Export all it's data to the newly created database.
4. Remove some records from the second database.
5. Write this code:

    TMS_MiscEntities db = new TMS_MiscEntities();
    TMS_MiscEntities dbCopy = new TMS_MiscEntities();
    dbCopy.Database.Connection.ConnectionString = db.Database.Connection.ConnectionString.Replace("initial catalog=TMS_Misc", "initial catalog=TMS_Misc_new");

    Response.Write(string.Format("DB 1 records: {0}<br/>", db.ZipCodes.Count()));
    Response.Write(string.Format("DB 2 records: {0}<br/>", dbCopy.ZipCodes.Count()));

6。检查结果：

6. Check results:

DB 1 records: 869164
DB 2 records: 868709

7。得出结论，它的工作原理：）

7. Conclude that it works :)

这是我的连接字符串的外观：

This is how my connection string looks:

<add name="TMS_MiscEntities" connectionString="metadata=res://*/DbModel.csdl|res://*/DbModel.ssdl|res://*/DbModel.msl;provider=System.Data.SqlClient;provider connection string=&quot;data source=ws2008;initial catalog=TMS_Misc;integrated security=True;MultipleActiveResultSets=True;App=EntityFramework&quot;" providerName="System.Data.EntityClient" />

这篇关于实体框架：多个数据库具有相同的架构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！