Oracle 1Z0-898 問題集

質問 1：
Given two entities with one to-one association:

Which code fragment correctly defines the detail field that PersonDetail instance in removed if the person instance that references it is removed?
A. @OneToOne (optional = false)
@mapsId
PersonDetail Detail;
B. @ OneToOne (cascade = ORPHAN _ DELETE)
@mapsId
PersonDetail detail;
C. @OneToOne (optional = false)
personDetail detail;
D. @ OneToOne (orphanremoval = true)
PersonDetail Detail;
正解：D

質問 2：
A developer wants to ensure that an entity's data is up-to-date with regard to the database. Which of the following statements is guaranteed to accomplish this?
A. Add acacheable (false) annotation on the entity class.
B. Call EntityManager.find on the entity.
C. Use a named query to retrieve the entity.
D. Call EntityManager.refresh on the entity.
正解：B

質問 3：
Persistence application locks entity x with a LockModeType. PESSIMISTIC_READ lock type, which statement is true?
A. If the application later updates the entity, and the changes are flushed to the database, the lock will be converted to an exclusive lock.
B. This operation will force serialization among transactions attempting to read the entity data.
C. This operation will result in a TransactionRolledbackException if the lock cannot be obtained.
D. LockModeType. PESSIMISTIC_READ is the synonym of the LockModeType.REA
正解：C

質問 4：
FooBean and BarBean are both EJB 3.0 stateless beans with container-managed transaction demarcation. All business methods in FooBean have transaction attribute REQUIRED, and all business methods in BarBean have transaction attribute REQUIRED_NEW. The business method foo in FooBean invokes the Business method bar in BarBean.
Given:
10.
Public class BarBean {
11.
public void bar () {
12.
throw new RuntimeException ("unexpected error . . . ");
13.
}}
Which is true about the method of invocation assuming execution reaches line 12?
A. FooBean.foo method receives javax.ejb.EJBException.
B. The BarBean bean instance is in ready state for the next invocation.
C. FooBean.foo method receives the original RuntimeException thrown from BarBean.bar method.
D. FooBean.foo method receives javax -ejb. EJBTtansactionRolledbackException.
正解：A

質問 5：
Which statement is correct about the Java Persistence API support for the SQL queries?
A. SQL queries are expected to be portable across databases.
B. Only SELECT SQL queries are required to be supported.
C. The result of an SQL query is not limited to entities.
D. SQL queries are NOT allowed to use parameters.
正解：C

質問 6：
Which two of the following statements are true of embeddable classes? (Choose two)
A. Null comparison operations over embeddable classes are not supported in the Java Persistence query language.
B. An embeddable class must not be used to represent the state of another embeddable class.
C. An embeddable class must not contain a relationship to an entity.
D. An embeddable class can be the key of a Map relationship.
正解：A,D