When using the Union All transformation editor in SSIS you’ll notice by default each input column is just named ‘Union All Input 1’, ‘Union All Input 2’ etc. (but not necessarily in that order) as shown below.
If you’ve got a lot of inputs this can be somewhat confusing as its harder to see which column corresponds to which of your source inputs. It’s easy to give your inputs a custom name however you can’t do it through the IDE as Visual Studio has the relevant Property (DestinationName) disabled. I don’t know why this is but I would be happy if anyone can tell me.
Updating DestinationName manually
In this case you can just manually edit the .dtsx package. Just search for name=”Union All Input X” and change that to whatever you want. In the below example I’ve changed DestinationName to ‘ABC Input’.
After you save and reload the package (you might have to reload the SSIS project in Visual Studio too) and go back into the Union All Transformation Editor you’ll see your custom input name.
