I found if entity is turned on soft deletion, then you will not be able to recreate an instance with same unique attribute even you’ve deleted the early one.
The doc said there are three ways to turn off it, but:
EntityManager is required to be used on middle tier, if we don’t have a middle tier, then it is opt out.
DataManager is seems perfect when you ready to manipulate data by code, what if it’s just standard
3. For collection datasource, I’ve tried to set soft deletion to false either in xml or in
of entity browser, but it seems not work, I still cannot recreate entity with same unique attribute once built before. For entity editor, there is no collection datasource at all.
BTW. I want to add a button besides, and let it truly purge/flush the unwanted soft deletions, then I can reuse the unique attribute, how to get it?
if entity is turned on soft deletion, then you will not be able to recreate an instance with same unique attribute even you’ve deleted the early one
This problem does not exist when you use PostgreSQL, Microsoft SQL Server or Oracle, because for these databases you can create unique indexes either with “where” clause or including DELETE_TS column. Studio does this automatically.
In HSQL and MySQL null values in unique index make rows non-unique, so there is no simple solution for uniqueness of soft-deleted entities. A possible workaround for MySQL is provided here: MySQL Database Specifics - CUBA Platform. Developer’s Manual. For HSQL we just ignore this problem because we think this database should be used for prototypes only.
I would like to have the opposite case - having an entity with entirely unique column, including soft deleted ones. Is there a way to tell Studio not to generate partial index with (where DELETE_TS is null) but rather create an ordinary one?
Yes, init scripts will contain indexes created by Studio rules. But you can drop them in the Init data (30.create-db.sql) script and create your own. This script is never touched by Studio, so you can keep your custom schema modifications in it.