Question

I’m getting the below error in my C#/ASP.NET project for some reason – presumably it’s relating to the SubString part of the query. However, ‘SageJobNo’ and ‘CutOffDate’ are always populated.

Error:

Invalid length parameter passed to the LEFT or SUBSTRING function.

And the code is below:

 IEnumerable<CcsVwICATimesheet> Timesheets = (from s in SageDC.CcsVwICATimesheets where s.Contract_Number.Substring(0, s.Contract_Number.IndexOf(" ")) == SageJobNo && s.Timesheet_Date <= CutOffDate select s);

    foreach (CcsVwICATimesheet Timesheet in Timesheets)
    {
         LabourCosts += (double)Timesheet.Cost_Value;
    }

EDIT: The error occurs on the ‘foreach’ line

Answer 1

If you don’t have any ' ' in your string IndexOf will return -1 and Substring will fail.

Edit
You can safeguard by checking if the string contains " ".

IEnumerable<CcsVwICATimesheet> Timesheets = 
    (from s in SageDC.CcsVwICATimesheets 
        where 
        (
        (s.Contract_Number.Contains(" ") && s.Contract_Number.Substring(0, s.Contract_Number.IndexOf(" ")) == SageJobNo)
        ||
        (!s.Contract_Number.Contains(" ") && s.Contract_Number == SageJobNo)
        )
        && s.Timesheet_Date <= CutOffDate select s);

If you prefer the ternary operator that could be used as well.

If you use Linq2Objects you can use s.Contract_Number.Split().First(), but LINQ can not translate that to SQL.