Question

Just getting started with Linq to SQL so forgive the newbie question. I’m trying to reproduce the following (working) query in Linq to SQL (VB.NET):

Select     f.Title,     TotalArea = Sum(c.Area) From Firms f Left Join Concessions c on c.FirmID = f.FirmID Group By f.Title Order by Sum(c.Area) DESC 

(A Firm has many Concessions; a Concession has an area in hectares. I want a list of Firms starting with the ones that have the greatest total area of all their concessions.)

I’m imagining something like this as the Linq to SQL equivalent (pseudo-code)

From f As Firm In Db.Firms _ Order By f.Concessions.Sum(Area) 

… but that’s not right. Can anyone point me in the right direction?

Answer 1

Answer

Here’s the correct Linq to SQL equivalent

From c In Concessions _ Join f In Firms on f.FirmID equals c.FirmID _ Group by f.Title _ Into TotalArea = sum(c.OfficialArea)  _ Order by TotalArea Descending _ Select Title, TotalArea 

Thanks to @CMS for pointing me to LinqPad – what a great tool. You just point it to your database and you’re off and running. Not only are hundreds of samples included, but you can run them against included live databases. I was able to arrive at the above query in just a few minutes starting from the provided samples.