SELECT 
(SELECT COUNT(*) FROM TableName WHERE CODE=a.CODE)AS [COUNT]
,*
FROM TableName as a
WHERE [ID] = '30BCA6A3-0B18-4224-9248-14E2CD3F20B6'

var query=from a in db.TableName
          where a.ID=="30BCA6A3-0B18-4224-9248-14E2CD3F20B6"
          select new 
        { 
            Count=db.TableName.Where(b=>b.CODE==a.CODE).Count(),
            a
        };