问题
I am using Entity Framework 5.0 for my project. I looked on the internet and I saw that for the entity framework data context there was another constructor that had a string parameter for the connection string.
On my generated data context I don't have such a constructor. I looked into the base DbContext and it has such a constructor.
Was the code generated wrong? I generated the code from a database. Could this be the cause?
Turns out that I can edit the code generation template file to add the new constructor. Now I have added the new constructor. The file is a MyDataContext.tt file under your edmx model. There you have c# code mixed with template code. You can copy the no argument constructor from there and paste it bellow. Then you can change it and add a string argument to it and pass that argument to the DbContext constructor like this : base(myString).
回答1:
You can add one as needed.
Check the generated file and add an overloaded constructor.
public YourContext(string connectionStr)
: base(connectionStr)
{
}
Probably better to define this in a partial class though, as every generation will require you to manually add it each time.
来源：https://stackoverflow.com/questions/14182091/no-constructor-with-a-connection-string-in-entity-framework-datacontext