I had successfully written my first master child example with hibernate. After few days I took it again and upgraded some libraries. No sure what did I do but I could never
Two solutions
1. use merge if you want to update the object
2. use save if you want to just save new object (make sure identity is null to let hibernate or database generate it)
3. if you are using mapping like
@OneToOne(fetch = FetchType.EAGER,cascade=CascadeType.ALL)
@JoinColumn(name = "stock_id")
Then use CascadeType.ALL to CascadeType.MERGE
thanks Shahid Abbasi