CODEWITHSUNDEEP
c#restasp.net-web-apiresponse
Moeez
Moeez

Reputation: 478

Web API giving null in response

I have developed a web api which takes two parameters of date time (starting and end), and then should give distinct records. 

public HttpResponseMessage GetMeterPing(DateTime start, DateTime end)
    {
        try
        {


            var startDateTime = start;
            var endDateTime = end;

            var result = medEntitites.tj_xhqd.Where(m => m.sjsj >= startDateTime && m.sjsj <= endDateTime)
                                             .OrderByDescending(o => o.sjsj)
                                             .Select(s => new { s.zdjh, s.sjsj, s.xhqd })
                                             .Distinct()
                                             .FirstOrDefault();                                             


            return Request.CreateResponse(HttpStatusCode.OK, new { data = result });


        }
        catch (Exception ex)
        {
            return Request.CreateErrorResponse(HttpStatusCode.NotFound, ex);
        }
    }

API URL: http://localhost:14909/api/meters/GetMeterPing/2018-04-28T00:00:00/2018-04-27T23:59:59

When I run this web-api it gives me

{"data":null}

Also while debugging it the result is also null

Any help would be highly appreciated

Upvotes: 0

Views: 1040

Answers (1)

K. Alan Bates
K. Alan Bates

Reputation: 3154

Your description of your problem sounds like the Linq query you are executing is not returning any results, so your call to FirstOrDefault is defaulting, which is to say it is returning null. You then perform no additional validations, and respond with the result of this line set as the value of an anonymous projection having a data property.

Upvotes: 5

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