Talk:EclipseLink/Development/2.4.0/JPA-RS/REST-API

--Tom.ware.oracle.com 15:24, 21 December 2011 (UTC) PUT should not be used for INSERT. PUT is supposed to be itempotent and because of the possibility of sequencing, creates are not itempotent.

• We should use PUT for update
• We should use POST for insert

--Doug 15:18, 21 December 2011 (UTC) This should relate to JPA and therefore:

• POST == EntityManager.persist
• PUT == EntityManager.merge

The side-effect of this is that a merge of a new entity can result in an INSERT.

--Tom.ware.oracle.com 15:24, 21 December 2011 (UTC)

• Should we try to guarantee itempotency on PUT?
  • A check for sequencing and then a does exist query?

--Doug 15:37, 21 December 2011 (UTC) I believe an em.merge does existence and sequence checking according to the descriptor's settings. I believe it would be idempotent for a new instance.

--Tom.ware.oracle.com 16:42, 21 December 2011 (UTC) I think if you merge an object that has sequencing with its id field unpopulated, an insert will happen and sequencing will populate the identity field - hence if I did two consecutive puts with the same JSON object (with no identity field populated), it would result in two creates - not itempotent.