Teach Yourself Borland C++ in 14 Days - portal

462 Day 12
statements are executed in the linked UpdateSQL component. Note that you can set up the
OnUpdateError event to handle errors that occur during a call to ApplyUpdates.
There are also a couple properties that relate directly to the use of cached updates with stored
procedures: CachedUpdates and UpdateRecordTypes. CachedUpdates toggles cached update
support for the StoredProc component. Unless CachedUpdates is enabled and you’ve linked
and set up an UpdateSQL component properly, you won’t be able to update stored procedure
result sets. UpdateRecordTypes determines which types of updates remain visible in a TDataset
with CachedUpdates set to true.
Updating read-only TDatasets is discussed further in the section on the UpdateSQL component
later today.
TBatchMove
Module: DBTables Class ancestor: TComponent
The TBatchMove component enables you to work with sets of records in operations between
two tables. These sets can range from a few records to all the records in a TDataset. When
working with TBatchMove, you specify both a source and a destination table. You can append,
update, and delete rows in the target table. You can even replace the target table completely
if you want to. The actual operation carried out when you call the component’s Execute
method depends on the setting of the Mode property.
Table 12.17 lists the key properties and Table 12.18 lists the key methods of the TBatchMove
component. This component has no key events.
Table 12.17. TBatchMove key properties.
Property Description
Destination Specifies the destination of the batch move operation.
Mapping Specifies column-to-column mappings between Source and Dest. If
your source and destination tables are not identical, you’ll need to
provide field mappings so that the BDE can figure out where to put
your data. If you neglect to do this with tables that aren’t identical,
the batch move will fail.
Mode Specifies the type of move (such as batAppendUpdate or batCopy).
Source Specifies the source of the batch move operation.