DataAdapter class. The data is read - only, which
is used by developers sometimes. And developers
seldom need to change it to data source of bottom
layer. In some situations which require to caching
data in memory in order to decrease times of
unchanged data that is called by database.
DataAdapter helps developers to deal with these
situations easily by the disconnect model,
DataAdapter fills DataSet object when a batch of
continuously changes which are read and write
operations to database return to database.
DataAadapter contains connecting objects and
references which are opened automatically or
closed when the database is reading or writing
.Moreover, DataAdapter contains references of
Command object of operations that are SELECT