Edit: If you’re using EntityFramework >= 6.0, use DbFunctions.AddDays
. For older versions of Entity Framework, use EntityFunctions.AddDays
:
var requestIgnored = context.Request
.Where(c => c.IdRequest == result.IdRequest
&& c.IdRequestTypes == 1
&& c.Accepted == false
&& DateTime.Now <= DbFunctions.AddDays(c.DateResponse, 30))
.SingleOrDefault();