Typed Dataset + DateTime-Column + NULL-Value = nowhere to go?

Question

Hi All,

I have a problem here. I get Data from an Oracle-Database, that my application progresses. One of the columns is a DateTime-Column.
Since I need to be able to store NULL into the database for that column, I set the DataType to String in my typed dataset (otherwise I won't be able to set it to null).

Now I can pick any row and set the Value of that column to null, but sending the data back to oracle will result in the following error : "ORA-1830 - date format picture ends before converting entire input string". So, setting it to DataType string in the DataSet causes a mess when sending it back to oracle.

From here, I tried a lot : Setting "null" or even "'null'" as a value, but I can't seem to find a solution for this specific problem. can anyone help me with this? how the hell will i get a NULL where i need it?

thanks a lot in advance,