Hibernate: create global temporary table HTE_book(rn_ integer not null, id bigint, version bigint, author varchar(255), title varchar(255), primary key (rn_)) transactional
Hibernate: create global temporary table HTE_widget_sequence(rn_ integer not null, id bigint, name varchar(255), primary key (rn_)) transactional
Hibernate: create table book (id bigint not null, author varchar(255), title varchar(255), version bigint not null, primary key (id))
Hibernate: create table widget_identity (id bigint generated by default as identity, name varchar(255), primary key (id))
Hibernate: create table widget_sequence (id bigint not null, name varchar(255), primary key (id))
Hibernate: create sequence book_seq start with 1 increment by 50
Hibernate: create sequence widget_seq start with 1 increment by 25
Hibernate: select next value for book_seq
Hibernate: /* insert for com.ankurm.hibernatedemo.model.Book */insert into book (author,title,version,id) values (?,?,?,?)
binding parameter (1:VARCHAR) <- [Robert C. Martin]
binding parameter (2:VARCHAR) <- [Clean Code]
binding parameter (3:BIGINT) <- [0]
binding parameter (4:BIGINT) <- [1]
SEED: inserted Book{id=1, title=Clean Code, author=Robert C. Martin, version=0}
--- Step 1: load the row, then close the session (entity is now detached) ---
Hibernate: select b1_0.id,b1_0.author,b1_0.title,b1_0.version from book b1_0 where b1_0.id=?
binding parameter (1:BIGINT) <- [1]
detached instance in hand: Book{id=1, title=Clean Code, author=Robert C. Martin, version=0}
--- Step 2: a second, independent session edits the same row and commits ---
Hibernate: select b1_0.id,b1_0.author,b1_0.title,b1_0.version from book b1_0 where b1_0.id=?
binding parameter (1:BIGINT) <- [1]
Hibernate: /* update for com.ankurm.hibernatedemo.model.Book */update book set author=?,title=?,version=? where id=? and version=?
binding parameter (1:VARCHAR) <- [Robert C. Martin]
binding parameter (2:VARCHAR) <- [Clean Code (2nd Edition)]
binding parameter (3:BIGINT) <- [1]
binding parameter (4:BIGINT) <- [1]
binding parameter (5:BIGINT) <- [0]
second session committed: Book{id=1, title=Clean Code (2nd Edition), author=Robert C. Martin, version=1} -- version column has now advanced in the database
--- Step 3: mutate the ORIGINAL detached instance (still holding the OLD version) and merge() it ---
detached instance before merge (note the version and title are both stale): Book{id=1, title=Clean Code, author=Robert C. Martin (Uncle Bob), version=0}
Hibernate: select b1_0.id,b1_0.author,b1_0.title,b1_0.version from book b1_0 where b1_0.id=?
binding parameter (1:BIGINT) <- [1]
merge() threw jakarta.persistence.OptimisticLockException: Row was already updated or deleted by another transaction for entity [com.ankurm.hibernatedemo.model.Book with id '1']
the title change from Step 2 survives untouched -- merge() refused to apply a write built on a stale version
--- Step 4: refresh() on a MANAGED entity with an unflushed local edit ---
Hibernate: select b1_0.id,b1_0.author,b1_0.title,b1_0.version from book b1_0 where b1_0.id=?
binding parameter (1:BIGINT) <- [1]
before refresh(): Book{id=1, title=Clean Code (2nd Edition), author=SOMEONE ELSE ENTIRELY (never flushed), version=1}
Hibernate: select b1_0.id,b1_0.author,b1_0.title,b1_0.version from book b1_0 where b1_0.id=?
binding parameter (1:BIGINT) <- [1]
after refresh():  Book{id=1, title=Clean Code (2nd Edition), author=Robert C. Martin, version=1} -- the local edit is gone, no exception was thrown