Columns as Variables
When using a formula, you can assign a variable to reference another column in the structure, including another formula column.
To assign a variable to another column, look for the Used in Columns section of the attribute selection drop-down.
The Used in Column attribute copies the existing column. It does not link to that column. This means:
- You can remove the original column without affecting your new formula. The calculations will continue to work just as they did at the moment you first configured the variable.
- If you update the original column and want that update reflected in your new column, you need to reassign the variable.
In the example above, we created a variable to track the results from the Epics Under/Over Time formula we created in our Formula Column article. If the original formula resulted in a negative value, this column will list a simple "WARNING" text flag. (You could also make this flag more effective with Wiki Markup!)
Once we've created our new formula column, if we make changes to the original Epic Under/Over Time column - or even delete it - our Epic Time Warning column will be unaffected. It will still give us a warning whenever we've spent too much time on a particular epic, because the new column (Epic Time Warning) continues to do all the calculations the original column did, even though the original column has changed.
If we want our Warning column updated based on the new changes, we'll need to assign the variable again.