Commit failed for grid with SQLContainer as Datasource

Hello!
I have a grid and a SQLCOntainer as datasource for it. I need to enble row editing and saving changes to the database.

I did following steps:

grid.setEditorEnabled(true);

and find on forum those sort of listener:

grid.getEditorFieldGroup().addCommitHandler(new FieldGroup.CommitHandler() {
               @Override
                public void preCommit(FieldGroup.CommitEvent commitEvent) throws     FieldGroup.CommitException {
                //...

               }

                @Override
               public void postCommit(FieldGroup.CommitEvent commitEvent) throws     FieldGroup.CommitException {
                //...
                   
                       try {
                            dbhelp.container.commit();
                            //dbhelp.q.beginTransaction();
                            //dbhelp.q.commit();
                        } catch (UnsupportedOperationException | SQLException e) {
                            // TODO Auto-generated catch block
                            e.printStackTrace();
                        }     
                    
               }
        });

and after i click "save" i got error:

com.vaadin.data.fieldgroup.FieldGroup$CommitException: Commit failed

and

Caused by: com.vaadin.data.util.sqlcontainer.OptimisticLockException: Someone else changed the row that was being updated.

q.setVersionColumn("upd_date"); 

upd_date is table in PostgreSQL with type timestamp with time zone and defult value set.

I would be much gratefull for the help!

Is there a possibility that someone else has in fact changed the data? 

Also, check that you've done this: https://vaadin.com/docs/-/part/framework/sqlcontainer/sqlcontainer-editing.html#sqlcontainer.editing.version-column