Join FirstOnly

[dns]

static void Job(Args _args)
{
    PurchTable      purchTable;
    PurchLine       purchLine;
    Counter         counter;
    ;
 
    while select
        purchTable
        group by PurchId
    join maxof(ItemId)
        from purchLine
            where purchLine.PurchId == purchTable.PurchId
    {
        counter ++;
        info(strfmt('%1  %2', purchTable.PurchId, purchLine.ItemId));
        if (counter == 20)
            break;
    }
}