Dataset xml null values

One of the XmlWriteMode values. The following example creates a System. FileStream object that is used to create a new XmlTextWriter. To write both data and schema, set the mode parameter to WriteSchema. To read just the schema, use the ReadXmlSchema method. FileIOPermission is not set to Write. A TextWriter object used to write the document. The following example first creates a simple DataSet with one DataTable , two columns, and ten rows. The DataSet schema and data are written to disk by invoking the WriteXml method.

A second DataSet is created and the ReadXml method is used to fill it with schema and data. A Stream object used to write to a file. To write both data and schema, use one of the overloads that includes the mode parameter, and set its value to WriteSchema.

The TextWriter object with which to write. FileStream object. This is all according to the documentation, so Microsoft isn't going to help us since they think this is to be the expected behavior. Martin Honnen led me on the way to the solution to my problem in his answer in this thread over at the MSDN forums.

To get NULL returned by the. This way I could make the. For the XML parser to understand that the xsi: prefix matches with the XMLSchema-instance name space we need to declare this namespace before we can execute the query. You can do this using the "with xmlnamespaces" clause. Here is the same example but now adapted with this new knowledge to retrieve a null value from the XML document:.

And the best thing is that this works identical for any type specified. Log in or register to rate. Join the discussion and add your comment.

Missing data is a difficult and common problem to solve. In this article, Joe Celko explains several approaches to deleting or replacing missing data. It sounds simple enough. Either your column will always have a value or it may not.

Sign in to vote. I'm using. Net 3. Thanks in advance Monday, April 23, PM. Data; using System. Forms; using System. Fill ds ; connection. Show ds. Show ex. WriteElementString "Discount", dr "Discount" ; xw. WriteElementString "Tax", dr "Tax" ; xw.