I have many requirements to be able to show on a ListView/Combobox the results from multiple joined tables. (e.g.Show Transactions but join in the Stock Description from a joined file). I have gone through a lot of the threads here to get hints , and have it working fine on a Combobox , but would like to ensure there are no Gotchas for any of the other list types , or maybe there is a better way.

 

Any comments would be helpful

As Greg pointed out the only issue is if you try to do an update, add or delete. The advantage of adding a dummy BO to the DDT is that all of the fields and property descriptors are generated for you. If you use scalar methods or add additional fields to your SELECT or stored procedures using a "real" BO, you have to add the custom properties and descriptors if you want to bind to them. However if you do an add, update, delete on a "real" BO, it will ignore the added fields. I've used both approaches. My only issue is that using the dummy BO results in "invalid" methods in the BO. At one time I was overriding the update, delete, and add methods to prevent any exception if they were called but I found it to be a lot of work. What I'd like to see is an additional BO class added to SF that was "read or lookup only" and had all of the add, delete, and update methods removed.

That's an excellent idea Larry. I second that suggestion!

Hi guys. Many thanks for all your comments which I have found very helpful.

The reson I thought that a Dummy BO would be the best of the available options to handle multiple joins is that it sems to be the most straightforward......just set up an additional Dummy BO with just one field...no need to set up views etc on the dataabase.

Also, these dummy BO would just be set up for lists (i.e. Read only) so unless I code something specifically in to 'Save' the Bo, there should be no possibility that attemps will be made to update the backend tables.....I will have a separate BO (the real BO) to do this.