AX / Dynamics 365 For Finance and Operations blog

//Step 1
//Declare a class variable 
//In the ClassDeclaration method of form declare a QueryBuildRange
class FormRun extends ObjectRun
{
    QueryBuildRange      qbdr;
}

//Step 2
//Initialize this range in the init method of datasource after super() call.
public void init()
{
    super();
    qbdr = InventSum_ds.queryBuildDataSource().addRange(fieldNum(InventSum, PhysicalInvent));
    qbdr.value(queryValue('>0')); //range value, in this case filter records that have PhysicalInvent Qty > 0

    InventSum_ds.executeQuery(); //execute Query

}