How to consume a webApi from asp.net Web API to store result in database?

In this tutorial is explained how to consume a web api with C#, in this example a console application is used, but you can also use another web api to consume of course.

http://www.asp.net/web-api/overview/web-api-clients/calling-a-web-api-from-a-net-client

You should have a look at the HttpClient

HttpClient client = new HttpClient();
client.BaseAddress = new Uri("http://localhost/yourwebapi");

Make sure your requests ask for the response in JSON using the Accept header like this:

client.DefaultRequestHeaders.Accept.Add(
new MediaTypeWithQualityHeaderValue("application/json"));

Now comes the part that differs from the tutorial, make sure you have the same objects as the other WEB API, if not, then you have to map the objects to your own objects. ASP.NET will convert the JSON you receive to the object you want it to be.

HttpResponseMessage response = client.GetAsync("api/yourcustomobjects").Result;
if (response.IsSuccessStatusCode)
{
    var yourcustomobjects = response.Content.ReadAsAsync<IEnumerable<YourCustomObject>>().Result;
    foreach (var x in yourcustomobjects)
    {
        //Call your store method and pass in your own object
        SaveCustomObjectToDB(x);
    }
}
else
{
    //Something has gone wrong, handle it here
}

please note that I use .Result for the case of the example. You should consider using the async await pattern here.