How can you update Database using DataAdapter and the DataSet?
Updating the Database with a DataAdapter and the DataSet
The Update method of the DataAdapter is called to resolve changes from a DataSet back to the data source. The Update method, like the Fill method, takes as arguments an instance of a DataSet, and an optional DataTable object or DataTable name. The DataSet instance is the DataSet that contains the changes that have been made, and the DataTable identifies the table from which to retrieve the changes.
When you call the Update method, the DataAdapter analyzes the changes that have been made and executes the appropriate command (INSERT, UPDATE, or DELETE). When the DataAdapter encounters a change to a DataRow, it uses the InsertCommand, UpdateCommand, or DeleteCommand to process the change.
The Update method will resolve your changes back to the data source, however other clients may have modified data at the data source since the last time you filled the DataSet. To refresh your DataSet with current data, use the DataAdapter and Fill the DataSet again. New rows will be added to the table, and updated information will be incorporated into existing rows. The Fill method determines whether a new row will be added or an existing row will be updated by examining the primary key values of the rows in the DataSet and the rows returned by the SelectCommand. If the Fill method encounters a primary key value for a row in the DataSet that matches a primary key value from a row in the results returned by the SelectCommand, it updates the existing row with the information from the row returned by the SelectCommand and sets the RowState of the existing row to Unchanged. If a row returned by the SelectCommand has a primary key value that does not match any of the primary key values of the rows in the DataSet, the Fill method adds a new row with a RowState of Unchanged.