Table is nullable DateTime, but DataSet throws an exception?

Question

I\'m attempting to use the DataSet designer to create a datatable from a query. I got this down just fine. The query used returns a nullable datetime column from the datab

Answer 1

It seems different with DataTable and Strongly Typed DataTable... Use Like this.

DataSet1.DataTable1DataTable table = new DataSet1.DataTable1DataTable();
table.Merge(adapter.GetData().CopyToDataTable());

Answer 2

Thanks this solved my similar issue : Here is the code. In case of this question

Isevent_start_date()

would return whether or not the field is null.

In my case: I had a similar problem and I used the following solution

            //Table's Name is Efforts,
            //Column's name is Target
            //So the dataset would automatically generate a property called IsTargetNull() which can be used to check nullables
            //Create an Adaptor
            EffortsTableAdapter ad = new EffortsTableAdapter();
            ProjectDashBoard.Db.EffortsDataTable efforts = ad.GetData();
            DataColumn targetColumn = new DataColumn();
            targetColumn = efforts.TargetColumn;

            List<DateTime?> targetTime = new List<DateTime?>();
            foreach (var item in efforts)
            {

                //----------------------------------------------------
                //This is the line that we are discussing about : 
                DateTime? myDateTime = item.IsTargetNull() ? null : (DateTime?)item.Target;
                //----------------------------------------------------

                targetTime.Add(myDateTime);

            }

Answer 3

I did this to insert value NULL in a DateTime column,

assuming that I have a nullable DateTime column in Database, I retrieved some data from the database in an object called response and I want to insert nullable DateTime value in the DataSet column that called RenewDate:

// create anew row of the same type of your table row
var rw = ds.StudentActionPrintDT.NewStudentActionPrintDTRow();

// check for null value
if(!response.RenewDate.HasValue)
{
  // if null, then the let DataSet to set it null by it's own way 
  rw.SetRenewDateNull();
}
else
{
  // if not null set value to the datetime value
  rw.RenewDate = response.RenewDate.Value;
}
// add the created row to the dateset [DataSetName].[ColumnName].Add[ColumnName]Row([The Created Row]);
ds.StudentActionPrintDT.AddStudentActionPrintDTRow(rw);