esamo If you want to add a column to the queue, you don't need to muck around with SQL queries - just edit the queue(s). In Admin -> Settings -> Tickets -> Queues select the queue you want to edit (probably a parent queue if you want it to apply to the children), select the Columns tab, then select 'Add new' at the bottom and choose Help Topic as the data source:
Select any filters and conditions as relevant, or just leave blank to get them all in standard formatting.