Server-side Grouping
Datagrid in this example is with Grouping feature turned-on. That is achieved by setting the dataSource's 'groupBy' property.
When a row is expanded the datagrid sends a request with the expanded row data object on the Server-Side Datasource. The server uses the SQL query sent by the Server-Side Datasource and returns the requested sub-rows collection.
This example uses a demo server with AlaSQL that generates SQL to show how a real server might use the requests sent by the Datagrid. The Server-Side Datagrid usage does not have any restrictions on the server-side technologies used.
SQL Query