Error deleting 'project'

[matthias-ronge]

Create a project, give the project to users, then click the trash. The project is no longer displayed, but an error message is displayed.

Stacktrace:

[ERROR] 2020-05-19 08:41:23.782 [ajp-nio-8009-exec-3] SqlExceptionHelper - Cannot delete
    or update a parent row: a foreign key constraint fails (`kitodo`.`project_x_template`,
    CONSTRAINT `FK_project_x_template_project_id` FOREIGN KEY (`project_id`) REFERENCES
    `project` (`id`))
[DEBUG] 2020-05-19 08:41:23.845 [ajp-nio-8009-exec-3] SearchService -
    org.kitodo.data.database.exceptions.DAOException:
    javax.persistence.PersistenceException:
    org.hibernate.exception.ConstraintViolationException: could not execute statement
[ERROR] 2020-05-19 08:41:23.845 [ajp-nio-8009-exec-3] ProjectForm - errorDeleting
    org.kitodo.data.exceptions.DataException: 
    org.kitodo.data.database.exceptions.DAOException: 
    javax.persistence.PersistenceException: 
    org.hibernate.exception.ConstraintViolationException: could not execute statement
    at org.kitodo.production.services.data.base.SearchService.remove
        (SearchService.java:334)
    at org.kitodo.production.services.data.ProjectService.delete(ProjectService.java:377)
    at org.kitodo.production.forms.ProjectForm.delete(ProjectForm.java:291)
    ...

After logout and login, the index must be updated because projects are not fully indexed. It looks like the project was deleted from the index, but not from the database. However, it is no longer displayed. It is probably no longer possible to create a new project with the name.

Goal: Delete project completely. If this is not possible, do not delete the project at all.

[solth]

Unfortunately this error does not seem to be fixed by #4665 after all. (still occurs in the current master)

[matthias-ronge]

Just tested: Not yet fixed.

Reason is that on duplicating a project, the process templates of the origin project are linked with the duplicated project as well. So the correct solution should be to remove the project to delete from any production templates, before deleting it. The underlying assumption is, that a project cannot be deleted if processes are linked to it.