Page History

...

Scrolling Result Set

 The Foundset maintains a scrollable interface for traversing record data. This interface includes a numeric index for every record that is returned by the Foundset's query.

Foundset Size

The Foundset also has a Size property, which indicates the number of records that are indexed by the Foundset at any given time. Because the Foundset's SQL query may eventually return thousands or millions of results, the initial size of the Foundset has a maximum of 200. This value can grow dynamically, in blocks of 200, as the Foundset is traversed.

Selected Index

The Foundset maintains a Selected Index, a cursor with which to step through the records. If the selected index equals or exceeds the size of the Foundset, the Foundset will automatically issue another query to load the next batch of primary key data. Thus the Foundset loads record data and grows dynamically with the changing Selected Index property. There are two methods used to get/set the foundsets selected index. They are getSelectedIndex and setSelectedIndex respectively.

Example: In the example below, note that the foundset's size changes after the selected index has changed. The foundset's cache grows dynamically

// Foundset size grows dynamically as the Foundset is traversed
foundset.getSize(); // returns 200
foundset.setSelectedIndex(200);
foundset.getSize(); // returns 400 because the foundset loaded the next 200 record pks

Iterating over a Foundset