Essential ADO.NET

6.8. Nonrelational Data and DataViews

DataViews do not work well with nonrelational DataTables—that is, Data-Tables that contain object data types or multivalued data. This is not surprising because the Sort and Filter syntax used in DataViews mimics SQL syntax defined in SQL-92. SQL-99 extends SQL to provide for embedded tables and object data types (user-defined types). To reference attributes of user-defined types, SQL-99 specifies that observer functions must be available. To update such types, you use mutator functions. Listing 6-25 presents an example of using a user-defined type in a SQL table definition and retrieving it through the mutator functions exposed by the database. (Note: No “mainstream” database exposes this functionality, ...