Feature request #15461
Relation reference widget: introduce unique constraint
|Pull Request or Patch supplied:||No||Resolution:||fixed/implemented|
In the relation reference widget it is possible to add new values without having to open the linked table first (comfortable).
We would, however, like to have a unique constraint on the "display expression"/"display column" to avoid double entries.
We need to discuss several options how to achieve this:
a) having a separate "value list manager" that takes care of it, but can also handle other stuff, like renaming/deleting values
b) Using the existing QGIS constraint mechanism (haven't found a way to check a newly entered value against other already existing values in the table though)
c) introducing a new "built in" Unique constraint on a table column