The Data Set instance is the Data Set that contains the changes that have been made, and the Data Table identifies the table from which to retrieve the changes.
If no Data Table is specified, the first Data Table in the Data Set is used.
If the Select Command returns the results of an OUTER JOIN, the Data Adapter will not set a Primary Key value for the resulting Data Table.
You must define the Primary Key yourself to ensure that duplicate rows are resolved correctly. To handle exceptions that may occur when calling the Update method, you can use the Row Updated event to respond to row update errors as they occur (see Handling Data Adapter Events), or you can set Data Adapter.
The Update method of the Data Adapter is called to resolve changes from a Data Set back to the data source.