Development and Production databases

问题

I and my team are currently doing a project, where we are using Entity Framework 4.1 (Code First). We want to write some tests, but we don't want them to run on our primary database, as we have a team in Singapore writing a client for what we do, and they are hitting that database constantly.

So to avoid disturbance when running our tests, we would like to have a different database for testing. How do we handle a second database when using Entity Framework? We want a solution that is semi-automatic (at least), so we don't have to fiddle around with Web.config each time we need to run tests.

回答1:

Fiddling around with the web.config can a process that is prone to error... unless you are using web.config Transformations that is.

I would create a new configuration, "Test" for your project in Visual Studio... it can be a copy of your existing development configuration (or Debug / Release, whatever). Then, right click your Web.config file in Solution Explorer and click Add Config Transforms. Follow the instructions here on how to write a transform file. If you only need to change the EF connection string for the test environment it would look something like this in web.Test.config:

<?xml version="1.0"?>
<configuration xmlns:xdt="http://schemas.microsoft.com/XML-Document-Transform">
<connectionStrings>
    <add name="AdventureWorksEntities" 
     connectionString="metadata=.\AdventureWorks.csdl|.\AdventureWorks.ssdl|.\AdventureWorks.msl;
     provider=System.Data.SqlClient;provider connection string='Data Source=TestDB;
     Initial Catalog=AdventureWorks;Integrated Security=True;Connection Timeout=60;
     multipleactiveresultsets=true'" providerName="System.Data.EntityClient" 
    xdt:Transform="SetAttributes" xdt:Locator="Match(name)"/>
</connectionStrings>

Just be sure to build under the correct configuration when you want to run your tests.

There is also a Visual Studio Add-in SlowCheetah Which makes this whole process very seamless from within the IDE.

回答2:

Solution apprehended from this post:

//Get the connection string from app.config and assign it to sqlconnection string builder
SqlConnectionStringBuilder sb = new SqlConnectionStringBuilder(((EntityConnection)context.Connection).StoreConnection.ConnectionString);
sb.IntegratedSecurity = false;
sb.UserID ="User1";
sb.Password = "Password1";

//set the object context connection string back from string builder. This will assign modified connection string.
((EntityConnection)context.Connection).StoreConnection.ConnectionString = sb.ConnectionString;

This allows you to change connection string at runtime. There are couple of other possible solutions:

1. Create a wrapper property around connection string. From tests, set it to a different value.
2. Use #IF TEST pragmas to specify correct connection string at compile-time

来源：https://stackoverflow.com/questions/9959081/development-and-production-databases