If you add a "Union All" task to your Data Flow the output columns get configured by the first input you connect to it.
However, if you later want to modify the input columns on the inputs (perhaps after adding an upstream Data Conversion) there seems to be no way to get it to forget the original set of output columns.
Ideally, there would be a button you can press to reset the output columns based on the earliest added input. At the very least it ought to forget its output columns when the last input is removed.
Other tasks offer a dialogue to resolve input / output mismatches but not Union All.
or am I missing something?
jks
If you right-click on a column name underneath "Output Column Name" you are given the option to delete that column.
Is that what you want?
-Jamie
|||I agree, while deleting or adding back one column is not the most painful process, many times while working on a package my upstream compenents changed a lot and I found myself deleting my Union All and Merge tasks and adding them back in because it was the easiest way to update them.
It would be nice if there was a refreash of some sort that would reexamine and update any added/deleted columns.
|||Thanks Jamie,
That helps - I had seen Delete in the right-click menu but it was always disabled when I needed it. Probably because I was trying to delete a new column I had just added without saving the task in between. I guess I'm used to records being committed when you move off them.
However, I still think it would be useful if Union All offered the same sort of intelligent reconfiguration options presented by other tasks. Any columns you've added to a data flow upstream ought to be propogated through the first input of a Union All to its output.
regards
jks
|||I can see why this (i.e. propogating the first input) would be useful but by the same token there may be people that would want the behaviour to be as it is now. As with most things you can't please all the people all of the time. Personally I think the functionality is fine as it is. Matter of opinion I guess.
Its worth saying that UNION ALL is an asynchronous component and this is the fundamental reason that any inputs don't automatically propogate through to the output. You'll find that the same is true of all asynchronous components.
-Jamie
|||Ok - I hadn't appreciated the distinction between sync and async components. If this is a consistent architectural feature I'll bite my tongue until I understand the architecture a little better!
This is just SSIS day 3 for me.
regards
jks
|||jks,
Well it sounds like you are headlong into it already. I recommend that you get your head around a few concepts pretty early. Namely:
The container hierarchysql