title: Dataset allowing Null values even when AllowDBNull = False?
body: <p>I have designed a dataset using VS2008 dataset designer. In one of the datatables, I have set "AllowDBNull" property of most of the columns to be False. However, still if I create a DataRow containing null values for these columns, this datatable accepts this row, without any error.</p>
  
  <p>Am I not understanding something here? Please advice. Thank you.</p>
  
  <p><b>Edit</b> Mike Spross' excellent explanation however, brings forth another question. How do we check text fields if they are System.DBNull? It is surprising that DataSets are not considering a string "" as System.DBNull and throwing an exception. Or is it not?</p>
  
  <p><b>Edit</b> I think I have found the problem and reason. I am initializing a new row of the DataTable, before filling in the values to that row. While initializing the row, default  value for string, ie, "" might be being filled in that column. I think that's it? Any ideas about this?</p>