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When a user types a value into a text field (which is bound to a specific column of the database table) and clicks out, the Servoy Application Server issues a SQL update command to the database to modify the selected record. The resulting change is also broadcast|display/DOCS/Data+Broadcasting||||||||||||||||||||||||||||||||||||\ to all connected clients.

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The fundamental unit of data binding in both the GUI and the API is the Servoy Foundset|display/DOCS/Foundsets+Concepts||||||||||||||||||||||||||||||||||||\ object.

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Foundsets are typically updated on a record-by-record basis, either as the user operates on a foundset-bound GUI component, or through programmatic interactions. However, sometimes it is necessary to perform an update to an entire foundset. For performance reasons, it is not advised that this be done by programmatically iterating over the foundset's records. Rather, it is recommended that batch updates be performed using the JSFoundsetUpdater API.

The Foundset Updater API is ideal to use for the following situations:

Updating an entire foundset

This essentially has the effect of issuing a SQL UPDATE statement using the WHERE clause that constrains the foundset. This presents a significant performance advantage over updating records individually. In the example below, a related foundset is updated, meaning all orders belonging to the selected customer will be affected.

var fsUpdater = databaseManager.getFoundSetUpdater(foundset);// Updates all the records in the foundsetvar fsUpdater = databaseManager.getFoundSetUpdater(customers_to_orders);
fsUpdater.setColumn('status',101);
fsUpdater.performUpdate();

Updating a partial foundset with different values for each record

The Foundset Updater API can also be used to update part of a foundset. Moreover, unlike the above example, this approach allows for different values for each record. In the example below, the first 4 records (starting from the selected index) are updated by specifying an array of values for each column that is affected.

//	update first four records
var fsUpdater = databaseManager.getFoundSetUpdater(foundset);
fsUpdater.setColumn('customer_type',[1,2,3,4]);
fsUpdater.setColumn('my_flag',new [1,0,1,0]);
fsUpdater.performUpdate();

Updating each record individually

The Foundset Updater API can also be used to update records individually, but still holds a performance advantage over iterating on a foundset, which has more overhead and can cause the foundset's cache size to increase unnecessarily. In the example below, each record in the foundset is updated with a unique value (A simple counter is incremented, which is arbitrary, but demonstrates that each record can be updated with a unique value.)

var count = 0;
var fsUpdater = databaseManager.getFoundSetUpdater(foundset)
while(fsUpdater.next())
{
	fsUpdater.setColumn('degrees',count++);
}

When using this approach, it matters what the selected index of the foundset is. The update will start with this record.

Find Mode

Find Mode is a special mode that can be assumed by a foundset object to perform data searches using a powerful, high-level abstraction. When in Find Mode, the foundset's Data Providers, normally used to read/write data, are instead used to enter search criteria. Any data provider can be assigned a search condition which should evaluate to a String, Number or Date. Because forms typically bind to a foundset, criteria may be entered from the GUI by the user or programmatically.

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