The two persistence standards in Java have very similar API's on the face of it. Here we give a comparison of the method calls and their equivalent in the other API.
| Operation | JDO | JPA |
|---|---|---|
| Persist Object | pm.makePersistent() | em.persist |
| Update Object | pm.makePersistent() | em.merge() |
| Remove Object | pm.deletePersistent() | em.remove() |
| Retrieve Object | pm.getObjectById() pm.getExtent() |
em.find() |
| Refresh Object | pm.refresh() | em.refresh() |
| Detach single Object | pm.detachCopy() | em.detach() |
| Flush changes | pm.flush() | em.flush() |
| Access transaction | pm.currentTransaction() | em.getTransaction() |
| New Query | pm.newQuery() | em.createQuery() |
| New Named Query | pm.newNamedQuery() | em.createNamedQuery() |
| New SQL Query | pm.newQuery() | em.createNativeQuery() |