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Home - General / All posts - Is there a way to edit expression of a computed field
Corentin85 post(s)
#03-Aug-20 14:37


I am computing several fields with the "edit expression" optino of the new field window from the schema window.

But it is a try and error work. I havn't find a way to correct an expression, the "Edit expression..." button is frozen after the field is created and computed... So each time I have a corection to made I have to create a new field copy past the old expression from the old field to the new one, correct the error and see if the result is correct.

Now what is tricky is that I set more or less my first field [A] and I am computing a second field ([B]) from this one. When I detect an error in the way A is written I have to create a NewA and then a NewB... I will have several linked field like that...

Is there a better way to do so?

Thanks for your help


6,206 post(s)
#03-Aug-20 15:20

Is there a better way to do so?

Yes, if you're trying things out, use the Expression tab in the Transform pane. Create a field of the desired type, and then fill it using the Expression tab. That's just a one-time deal, not dynamic like a computed field, but you can try it over and over, varying the Expression in trial and error fashion, until you get it to work the way you want. You can then use that Expression as the basis for a computed field in the Schema dialog.


9,415 post(s)
#13-Aug-20 13:50

In addition to what Dimitri suggested, you might simply try writing a SELECT query that would compute the desired expression - adjust it until you are happy with the result and then create the computed field.

In general though, allowing to edit the expression of an existing computed field might not be a bad idea, provided the field is not used in other computed fields / btree indexes which do not allow nulls or duplicates / constraints (because they might break). We might allow doing that in the future.

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