tailieunhanh - The Managed Provider and Generic Data Set Classes

The Managed Provider and Generic Data Set Classes To provide both connected and disconnected database access, defines two sets of classes: managed provider and generic data. | The Managed Provider and Generic Data Set Classes To provide both connected and disconnected database access defines two sets of classes managed provider and generic data. You use objects of the managed provider classes to directly connect to a database and to synchronize your locally stored data with the database. You can use the managed provider classes to read rows from the database in a forward-only direction. You use a different set of managed provider classes depending on the database you use. You use objects of the generic data classes to store a local copy of the information retrieved from the database. This copy is stored in the memory of the computer where the C program is running. The main generic data class is the class. The generic data classes as their name suggests are not specific to any database and you always use the same classes regardless of the database you use. The generic data classes represent information retrieved from the database as XML. The Managed Provider Classes The managed provider objects allow you to directly access a database and you ll be introduced to the classes that allow you to create these objects in this section. You use the managed provider objects to connect to the database and read and write information to and from the database. Figure illustrates some of the managed provider objects and how they relate to each other. Figure Some of the managed provider objects There are currently three sets of managed provider classes and each set is designed to work with different database standards SQL Server Managed Provider Classes You use the SQL Server managed provider classes to connect to a SQL Server database. OLE DB Managed Provider Classes You use the OLE DB Object Linking and Embedding for Databases managed provider classes to connect to any database that supports OLE DB such as Access or Oracle. ODBC Managed Provider Classes You use the ODBC Open Database Connectivity managed provider .