Question

I have strongly typed dataset. Now I want to do a select on a datatable with linq.

My problem is that this table have numeric columns that allows null-values. But if there are datarows that have in this columns no values, I don’t know to make the Select- command.

This is my query:

var query = from tab1 in localDataSet.simpleTable
            select new {
               line = tab1.IsLineNull ? null : tab1.line,
               wait = tab1.IswaitNull() ? null : tab1.wait
            }

I can’t set line = null if tab1.IsLineNull() returns true, because the datatype ‘decimal’ (and all other number valuetypes) can’t be null. But what should I choose instead? I can’t choose 0 either.

Answer 1

I assume that you don’t know how to create a Nullable<T>:

var query = from tab1 in localDataSet.simpleTable
        select new {
           line = tab1.IsLineNull ?   new Nullable<decimal>(): tab1.line,
           wait = tab1.IswaitNull() ? new Nullable<decimal>(): tab1.wait
        }