Enthuware

Hi,

I think the last choice is also correct, can anyone explain why it is wrong?

private Integer acctid;
private Double balance;

public Integer getAcctid() { return this.acctid; }
public void setAcctid(Integer acctid) { this.acctid = acctid; }

public Double getBalance() { return this.balance; }
public void setBalance(Double balance) { this.balance = balance; }

Because there are 2 mandatory annotations for ANY entity:

1) @Entity annotation on class (it's assumed in question, just does not shown)
2) Primary key annotation - most often @Id is used, however any of these are possible: @Id, @IdClass, @EmbeddedId

Since the mentioned option does not have PK annotation, it's invalid -- JPA provider does not know how to handle the entity.

One more clarification: @IdClass used only in combination with @Id

It's clear

After a second thought, I think you're right - option D also can be selected as correct.

We can define Promary Key information in deployment descriptor (like orm.xml)

Persistence provider uses combination (union) of annotations and XML mappings for it's work (XML has precedence).

So, I think it's a valid situation (although I would say crazy) when developer defines @Entity via annotation, and ID defined like this in orm.xml:
The question must be more specific if no mapping information is provided in XML.

The question has been updated to make it clear that no mapping information is provided in XML.

thank you for your feedback!

OK, thanks!

PS I have passed the exam with score 96%

Wow ! Congratulations !!!

Your score even better than mine (I got 91%)