Sequence operators not supported for type 'System.String'.

Question

There is a composite primary key on the columns in the where condition of the below code so there can be only one possible return value. I am returning by SingleOrDefault but at run time I am getting the error in the question title: "Sequence operators not supported for type 'System.String'." I'm pretty new to LINQ so might have got the syntax wrong? Any help appreciated

 using (myContext Data = new myContext())
    {
        string Result = (from d in Data.myTable 
                    where d.textColumn == myDropDownList.SelectedValue && d.intColumn == 1
                    select d.anotherTextColumn.SingleOrDefault()).ToString();
    }

Answer 1

You're almost there - you need to call SingleOrDefault() on the query object instead of calling it on string object:

string Result = (from d in Data.myTable 
                where d.textColumn == myDropDownList.SelectedValue && d.intColumn == 1
                select d.anotherTextColumn).SingleOrDefault();