...

A Servoy Form is typically bound to a single database table and the form will always contain a single Foundset object foundset which is bound to the same table. Much of the action in the user interface, such as a user editing data fields, directly affects the form's foundset. Conversely, actions taken on the foundset, such as programmatically editing data, is immediately reflected in the form.

...

One of the primary jobs of a Foundset foundset is to load records from the table to which it is bound. A Foundset object foundset is always based on an underlying SQL query, which may change often during the lifetime of the Foundsetfoundset. However the query will always take the form of selecting the Primary Key column(s) from the table and will also always include an Order By an ORDER BY clause, which in its simplest form will sort the results based on the Primary Key column(s).

...

After retrieving the results for Primary Key data, the Foundset foundset will issue subsequent SQL queries to load the matching record data in smaller, optimized blocks. This query happens automatically in an on-demand fashion to satisfy the Foundsetfoundset's scrollable interface.

SELECT * FROM customers WHERE customerid IN (?,?,?,?,?,?,?,?) ORDER BY customerid ASC

A foundset's underlying query can change dramatically throughout the client session. The following events will modify a foundset's underlying query:

• When a form to which it is bound is loaded
• When the loadRecords method is called programmatically
• When the sort definition is changed
• When it exits find mode

...

Loading Records Programmatically

The The loadRecords method is used to directly modify the underlying query that loads PK data. There are several uses.

...

Scrolling Result Set

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

Foundset Size

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

Selected Index

The Foundset foundset maintains a Selected Indexselected index, a cursor with which to step through the records. If the selected index equals or exceeds the size of the Foundsetfoundset, the Foundset foundset will automatically issue another query to load the next batch of primary key data. Thus the Foundset 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.

...

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

...

Foundsets are often constrained or filtered by a Relation. In this situation, the foundset is said to be a Related Foundset and its default SQL query will include in its Where Clauseits WHERE clause, the parameters by which to constrain the foundset.

...

Foundsets and Data Broadcasting

A Foundset foundset may be automatically updated when the client receives a Data Broadcast Event . If the data change affected the table to which the foundset is bound, the foundset will be refreshed to reflect the change.

...