How to delete/remove a hidden element in the openLCA structure?

Question

When working in openLCA environment frequently I have to delete elements (flows, processes, product systems) created by me. Deleting requires attention as the elements are linked among themselves, and the deletion process is time consuming.
Recently I met a problem and I can’t solve still it. I hope here I could get advice on how to proceed.
The problem: I can’t delete a process because I get the message “The selected element cannot be deleted because it is used in other data sets.”
In the usage window for the process, I see the name of the product system to which the process is being linked to. That product system can be opened if I click its name. I call that product system “hidden element” because it does not exist in the Product systems category of the Navigation pane and I cannot delete it.  So I got a loop: the process that has to be deleted requires deletion of an element that is hidden and can’t be deleted!!??
Can someone give me advice on what could be done in that case?
Thanks.
Chris P

Answer 1

Hi Christo,
that happens in 1.4 if you move a product system and do not insert it back again. Making it visible is possible but requires use of the developer tools. Basically in SQL:

select * from tbl_categories where model_type = `PRODUCT_SYSTEM`

-> shows the categories in use for the product systemss

select * from tbl_product_systems

-> shows all your product systems; find the one that is lost

update tbl_product_systems set f_category = ###any the number from the first query that you see as category### where ID = ##here the number of the hidden product system###

-> update to a category that is shown

And I would recommend to switch to a newer version of openLCA!
Best wishes,
Andreas

Comments

Hi Andreas,
Thanks for your prompt reply of my question.
Unfortunately I do not have any version of SQL server installed on my PC.  Also, I have no experience about working with that developer tool. So, I think it will take me hours to use the coding approach.
Furthermore, I use the openLCA v.1.4 for self-education purpose, when I find myself experienced enough - then I’ll change my computer by a more powerful one and go to version 1.5 or maybe the newest v.1.6 .
Until then, I consider creating a new process which is not linked to the hidden product system that troubled me. The new process will permit me to create a new product system and thus to continue my current (dummy) project work. I think such an indirect approach may be helpful.

Chris P

---

Hi, no need to use MS SQL server or similar, I mean the developer interface in openLCA. openLCA 1.5 (or, 1.6 which we released yesterday) is more resource efficient thus I would not wait until you have a more powerful computer.
Best
Andreas