Opening a DbContext connection within an existing SqlConnection

Question

I\'m interested if opening an Entity Framework\'s DbContext connection within an existing ADO.NET SqlConnection should be discouraged, provided tha

Answer 1

The connection string is not the connection. You never pass the actual connection to the context, so it has to create a new one. As a consequence, the transaction will escalate to a distributed transaction in order to cover both connections.

You need to pass the actual connection object to the context, using the appropriate constructor. In this case there will be only a single local transaction and no need to escalate it to a distributed transaction.

In EF6+ you can simply pass the connection object. Change your method to this:

void DoStuffWithEF(SqlConnection connection)
{
    using(var context=new MyCodeFirstDbContext(connection,false)
    {
    // ...
    }
}

In previous versions you couldn't pass an open connection which required some unpleasant gymnastics, as described here