specified cast is not valid in linq to sql

Question

I used this code:

int i = Int32.Parse(dataGridView2.Rows[rowID].Cells["ProfID"].Value.ToString());
var db = new bouDataDataContext();
var sel = db.Payments.Where(c => c.WTID == wtID && c.ProfID == i).Single();

and c.WTID is defined as integer in the database but I receive this error:

specified Cast is not a valid

Answer 1

i think it's because you are doing

c.ProfID == i

where c.ProfID is a string, and i is an integer, if not then

var sel = db.Payments.Where(c => c.WTID == (int)wtID && c.ProfID == i).Single();

should work, that is, if wtID can be casted to integer