Hibernate的Session脏检查问题

Question

Hibernate的Session是怎么判断一个对象是新建还是一个dirty,其原理是怎样的

Answer 1

When session.load(obj), a copy of the loaded object (a snapshot) is made (see SessionImpl.initializeEntity() ), when session.flush(), all objects in session are compared to their saved snapshots to see if their property values have changed (dirty), if yes then that object's dirty properties will be updated in SQL (see SessionImpl.flushEntity()).