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POHow to set variables dynamically using Entity Framework 5 & Linq
 

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  1. POHow to set variables dynamically using Entity Framework 5 & Linq
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    <p>How would I set the latitude &amp; longitude of the "sourcePoint" dynamically?</p> <p>I can query database to get the info I need (the latitude &amp; longitude) but I am not sure how to set the sourcePoint dynamically using those values.</p> <p>This is my first shot at C#, MVC 4, Entity Framework 5 &amp; Linq so I would appreciate some help on this one. Thanks for your help in advance :)</p> <pre><code> public ActionResult Index(string location = "melbourne-vic-3000") { ////get the latitude &amp; longitude of the current location //var latlong = // (from u in db.Locations // where u.Url.Equals(location) // select u).Take(1); //set the latitude &amp; longitude of the sourcePoint var sourcePoint = GeoUtils.CreatePoint(-37.815206, 144.963937); //***NEED TO GET THE LATITUDE &amp; LONITUDE FROM THE DATABASE (see query above)*** //work out the distance each business is from the sourcePoint var model = from x in db.Businesses from y in db.Locations where location == y.Url select new BusinessDistance { BusinessName = x.BusinessName, Address = x.Address, Distance = Math.Round((x.GeoLocation.Distance(sourcePoint).Value / 1000), 2) }; return View(model.ToList()); } </code></pre> <hr> <h2>---- working code ----</h2> <pre><code> public ActionResult Index(string location = null) { var sourcePoint = GeoUtils.CreatePoint(-37.815206, 144.963937); //Set the default latitude &amp; longitude to Melbourne //get the latitude &amp; longitude of the current location from the database var latlong = (from u in db.Locations where u.Url.Equals(location) select u).FirstOrDefault(); if (latlong != null) { //dynamically set the latitude &amp; longitude of the sourcePoint using the latitude &amp; longitude we got from the database sourcePoint = GeoUtils.CreatePoint((float)Convert.ToDouble(latlong.Latitude), (float)Convert.ToDouble(latlong.Longitude)); } //work out the distance each business is from the sourcePoint var model = from x in db.Businesses from y in db.Locations where location == y.Url select new BusinessDistance { LocationSuburb = y.Suburb, BusinessName = x.BusinessName, Address = x.Address, Distance = Math.Round((x.GeoLocation.Distance(sourcePoint).Value / 1000), 2) }; if (model != null) { return View(model.ToList()); } else { //display the error page return View(); //TO DO... } } </code></pre>
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