Sometimes a column (or columns) can be optional in source data. Here is an example that performs a calculation when an optional column exists in a source dataset and does nothing when it’s missing.
To see the change in behavior enable/disable the 2nd step in table “Source data” - it will add/remove an optional column.
optional-column-calculation.morph (3.6 KB)
Optional column exists:
Optional column is missing:
The example is simplified using the recently added action “Skip on condition” and the columnexists() function:
optional-column-calculation.morph (2.7 KB)
As with the previous example, enable/disable the 2nd action in the “Sample data” table to simulate an optional column.
The optional column is present:
The optional column is missing:
One more solution - if a column is missing, create it with a dummy value. In this case you can ensure that a column is always present.
