I would like to translate the following SQL into LINQ:
SELECT
(Select count(BidID)) as TotalBidNum,
(Select sum(Amount)) as TotalBidVal
FROM Bids
You could try this out. The variable b is an entity (for every iteration) while ctx is an entityset which has the extension methods you need.
var ctx = _dataContext.Bids;
var result = ctx
.Select( x => new
{
TotalBidVal = ctx.Sum ( p => p.Amount ),
TotalBidNum = ctx.Count( p => p.BidId )
} )
.First();