Ran into this issue last night and just figured it out. I have this code for a demo:
<span style="color: #0000ff">using</span> System;<br /><span style="color: #0000ff">using</span> System.Data.Objects;<br /><span style="color: #0000ff">using</span> System.Transactions;<br /><span style="color: #0000ff">using</span> ExtractTransformLoad.Domain;<br /><span style="color: #0000ff">using</span> Northwind.Entities;<br /><span style="color: #008000">//using System.Linq;</span><br /><br /><span style="color: #0000ff">namespace</span> ExtractTransformLoad<br />{<br /> <span style="color: #0000ff">public</span> <span style="color: #0000ff">class</span> SqlFreightByShipperRepository: IFreightByShipperRepository<br /> {<br /> <span style="color: #0000ff">public</span> <span style="color: #0000ff">void</span> DeleteAndInsert(DateTime runDate, FreightByShipper freightByShipper)<br /> {<br /> <span style="color: #0000ff">using</span> (var context = <span style="color: #0000ff">new</span> NorthwindEntities())<br /> <span style="color: #0000ff">using</span> (var scope = <span style="color: #0000ff">new</span> TransactionScope())<br /> {<br /> var summaryToDelete = (from freightSummary <span style="color: #0000ff">in</span> context.FreightSummaries<br /> <span style="color: #0000ff">where</span><br /> freightSummary.RunDate == runDate &&<br /> freightSummary.ShipperName == freightByShipper.ShipperName<br /><br /> select freightSummary);<span style="color: #008000">//.FirstOrDefault();</span><br /> context.DeleteObject(summaryToDelete);<br /><br /> var newFreightSummary = <span style="color: #0000ff">new</span> FreightSummary()<br /> {<br /> Freight = freightByShipper.Freight,<br /> RunDate = DateTime.Today,<br /> ShipperName = freightByShipper.ShipperName<br /> };<br /> context.FreightSummaries.AddObject(newFreightSummary);<br /> context.SaveChanges(SaveOptions.AcceptAllChangesAfterSave);<br /> scope.Complete();<br /> }<br /> }<br /> }<br />}
Now, in Visual Studio, it looks like this:
Hovering over freightSummary in the above LINQ query would reveal just
(range variable)? freightSummary
A bunch of searching later didn’t much help, although this thread did put me on the right track just a moment ago. The trick, it turns out, is that I didn’t have the System.Linq namespace included (you can see above I just re-commented it out). If you include System.Linq, everything works as expected. Final code here:
<span style="color: #0000ff">using</span> System;<br /><span style="color: #0000ff">using</span> System.Data.Objects;<br /><span style="color: #0000ff">using</span> System.Transactions;<br /><span style="color: #0000ff">using</span> ExtractTransformLoad.Domain;<br /><span style="color: #0000ff">using</span> Northwind.Entities;<br /><span style="color: #0000ff">using</span> System.Linq;<br /><br /><span style="color: #0000ff">namespace</span> ExtractTransformLoad<br />{<br /> <span style="color: #0000ff">public</span> <span style="color: #0000ff">class</span> SqlFreightByShipperRepository: IFreightByShipperRepository<br /> {<br /> <span style="color: #0000ff">public</span> <span style="color: #0000ff">void</span> DeleteAndInsert(DateTime runDate, FreightByShipper freightByShipper)<br /> {<br /> <span style="color: #0000ff">using</span> (var context = <span style="color: #0000ff">new</span> NorthwindEntities())<br /> <span style="color: #0000ff">using</span> (var scope = <span style="color: #0000ff">new</span> TransactionScope())<br /> {<br /> var summaryToDelete = (from freightSummary <span style="color: #0000ff">in</span> context.FreightSummaries<br /> <span style="color: #0000ff">where</span><br /> freightSummary.RunDate == runDate &&<br /> freightSummary.ShipperName == freightByShipper.ShipperName<br /><br /> select freightSummary).FirstOrDefault();<br /> context.DeleteObject(summaryToDelete);<br /><br /> var newFreightSummary = <span style="color: #0000ff">new</span> FreightSummary()<br /> {<br /> Freight = freightByShipper.Freight,<br /> RunDate = DateTime.Today,<br /> ShipperName = freightByShipper.ShipperName<br /> };<br /> context.FreightSummaries.AddObject(newFreightSummary);<br /> context.SaveChanges(SaveOptions.AcceptAllChangesAfterSave);<br /> scope.Complete();<br /> }<br /> }<br /> }<br />}
I guess I’m spoiled by Resharper, which normally prompts me for any namespace it detects that I’m trying to use but haven’t yet included. It wasn’t until I added the.FirstOrDefault() that R# kicked in, and then for some reason it couldn’t automatically add the using statement for System.Linq, but once I did so by hand, the Range Variable problem disappeared.