This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
It seems like referencedColumnName element can be missing in @OneToOne @JoinColumn too. What confusing me is when I point out the referencedColumnName I encounter an error because the referenced column is generated with a wrong type.