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Loading Records

One of the primary jobs of a Foundset is to load records from the table to which it is bound. A Foundset object is always based on an underlying SQL query, which may change often during the lifetime of the Foundset. 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 clause, which in its simplest form will sort the results based on the Primary Key column(s).

SELECT customerid FROM customers ORDER BY customerid ASC

After retrieving the results for Primary Key data, the 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 Foundset'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 loadRecords method is used to directly modify the underlying query that loads PK data. There are several uses.

Load by a single PK

This is the simplest approach, which loads a single recordy by its primary key value.

foundset.loadRecords(123);

Load by PK data set

This approach simply dictates that a foundset will load records based on specified primary key data.

var ids = [1,2,3,6,9]; 				// an array of record PKs
var ds = databaseManager.convertToDataSet(ids); // convert the ids to a JSDataset
foundset.loadRecords(ds);			// load records

Load by another foundset

This approach is useful to essentially copy the query of another foundset.

foundset.loadRecords(anotherFoundset);

Load by Query

This approach allows a SQL query fragment to be used to set the foundset's underlying query. There are certain restriction on the form that a query can take. For obvious reasons, the query must return the primary key column(s) from the table to which the foundset is bound. For a full description see the reference guide.

var sql = 'select id from my_table where my_table.column1 in ?,?,?;
var args = [1,2,3];
foundset.loadRecords(sql, args);

Sorting