实体框架中的共享连接字符串

Question

I want to create a single connectionString in my Web.config and then re-use it in the "provider connection string" attribute of all Modules declarations.

example : Declare a connection string this way:

<add name="MyConnectionString" connectionString="Data Source=.;Initial
Catalog=MyDB;User ID=username;Password=pwd;" />

and then share this connection between modules:

<add name="Module1Context" connectionString="metadata=res//*/Module1.csdl| ... | 
...;provider=System.Data.SqlClient;provider connection string=MyConnectionString" 
providerName="System.Data.EntityClient" />

Is this possible?

Answer 1

您可以使用ConfigurationManager.ConnectionStrings在运行时管理连接字符串http://msdn.microsoft.com/en-us/library/system.configuration.configurationmanager.connectionstrings.aspx

Answer 2

It's not directly possible the way you have it described above.

The solution for this is almost certainly going to be FAR more work than just copying your connection strings, commenting or uncommenting entries as you go.

Be sure you are using Configuration Transformation files to manage this.

If you really must do this, then you will need to build the connection strings yourself, using the EntityConnectionStringBuilder class, pulling the provider connection string from your MyConnectionString value. Set the EntityConnection property in your context object when you instantiate it; see http://msdn.microsoft.com/en-us/library/bb896325.aspx for details.