How to count the number of trues in a table in LINQ to SQL

Question

I have a table like this

 StudID   Date      I  II  III  IV   V   VI   VII  VIII 
-------------------------------------------------------------- 
  100    2-10-11    T   T   F    F   F   F     F     T
  101    2-10-11    T   T   T    F   F   F     F     T
  100    3-10-11    T   F   F    F   F   F     F     T
  100    4-10-11    T   F   F    F   F   F     F     T

Now i need to get the number of T's i.e, Trues in the table for a particular student in a particular month StudID is a varchar field Date is a datetime field and all the other datatype with bit

any ideas?

Answer 1

As the comments suggest, you should normalize your data.

However if you are unable to do that, you simply need to count the number of trues in each row.

context.Studs.Sum(s => (s.I ? 1 : 0) + (s.II ? 1 : 0) + ... + (s.VIII ? 1 : 0));

edit: To restrict the sum based on StudID and the month, you would use a Where operator

var id = "100";
var month = 10;

var set = context.Studs.Where(s => s.StudID == id;
set = set.Where(s => s.Date.Month == month);

return set.Sum(s => (s.I ? 1 : 0) + (s.II ? 1 : 0) + ... + (s.VIII ? 1 : 0));

Answer 2

var numberOfTrues = context.Students.
Where(x => x.StudID == 123 && x.Date.Month == studentMonth).
Sum(x => x.I.ToInt() + x.II.ToInt() + ... + x.VIII.ToInt());


// Add extension method    
public static int ToInt(this bool value)
{
   return value ? 1 : 0;
}