entity framework - Self hosted owin webapi app cannot find connection string in web.config -

my webapi application, runs fine when launched visual studio throws following error when running on owin self host:

"no connection string named 'productsdbcontext' found in application config file."

does owin need configuration access web.config file?

here startup.cs:

    public void configuration(iappbuilder appbuilder)     {         // configure web api self-host.          var config = new httpconfiguration();          webapiconfig.register(config);         unityconfig.registercomponents(config);         appbuilder.usewebapi(config);     }  

and self host code:

    [testmethod]     public void listscorecardslices()     {         var baseaddress = "http://localhost:9000/";          // start owin host          using (webapp.start<startup>(baseaddress))         {              httpclient client = new httpclient();              var response = client.getasync(baseaddress + "api/products(2)").result;             var responsebody = response.content.readasstringasync().result;             assert.areequal(httpstatuscode.ok, response.statuscode);         }     } 

if hosting owin in kind of service or non-web application (which likely, because why else need self-host), you'd need not web.config file, application config file, has name of <your executable name extension>.config. if add app.config file executable project, visual studio automatically place executable.