Question

I have the following LINQ-to-SQL query:

from cms in ConsignmentMarginBreakdowns.Where(a => a.BreakdownType == 'S')
from cmc in ConsignmentMarginBreakdowns.Where(a => a.BreakdownType == 'C')
where cms.TripNumber == cmc.TripNumber && cms.Depot == cmc.Depot && cms.TripDate == cmc.TripDate
select new
{
    NTConsignment = cms.NTConsignment,
    Depot = cms.Depot,
    TripNumber = cms.TripNumber,
    TripDate = cms.TripDate,
    Sales = cms.Value,
    Costs = cmc.Value,
    Margin = cms.Value - cmc.Value
}   

The ‘BreakdownType’ field is of ‘char(1)’ type in SQL Server 2008. For some reason, the query brings back no results as it is. To get it to bring back results, I need to change the top 2 lines to the following, which I imagine lowers the speed of the query:

from cms in ConsignmentMarginBreakdowns.Where(a => a.BreakdownType.ToString() == "S")
from cmc in ConsignmentMarginBreakdowns.Where(a => a.BreakdownType.ToString() == "C")

Why is this?

Answer 1

You say, “The ‘BreakdownType’ field is of char(1) type in SQL Server 2008″, what means that it’s a “Fixed-length, non-Unicode character data with a length of n bytes” (in your case 1), it actually doesn’t say that it’s a “char” just because of the length of 1.

See MSDN Docs.