Local Schema Sample

Purpose

A simple demo showing the use of several Data Abstract components to select/update a range of Customer records.

Examine the Code

The Data Abstract components on the form are:

• TDAConnectionManager: examine its Connections property - this has a standard collections property editor and Connections[0].ConnectionString supplies an ADO connection to Northwind. If you change this to a different driver, you will need to drop the appropriate driver on the form.
• TDADriverManager: a singleton component that manages the drivers used by the application. Set AutoLoad to True and DriverDirectory to your folder containing .DAD files to be loaded when the application starts.
• TDAADODriver: supports ADO databases. You can drop other drivers onto the form, e.g. TDAIBXDriver, TDADBXDriver etc.
• TDABinDataStreamer: handles the transfer of binary data packets. Note the events provided - they allow you to access/modify the data packets before and after transmission.
• TDASchema: manages the datasets available. Double click on its icon to invoke the Schema Modeler.
• TDABusinessProcessor: handles dataset updates. Its Schema component is set first followed by ReferencedDataSet.
• TDACDSDataTable: a DataAbstract aware descendant of the standard ClientDataSet.
• TDADataSource: a DataSource descendant that works with DataTables.