springmvc+jpa+springdata中遇到的错误解决办法

1、

Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'studentServiceBean': Invocation of init method failed; nested exception is java.lang.IllegalArgumentException:
Validation failed for query for method public abstract boxfish.bean.Student boxfish.service.StudentServiceBean.find(java.lang.String)!

原因：bean类中的扩展查询方法的query语句中的sql语句存在错误。

查询语句应该为select s from Student s where s.id=?1这种样式。其中表明Stduent必须和实体类名完全相同，否则报错。

2、Executing an update/delete query; nested exception is javax.persistence.TransactionRequiredException: Executing an update/delete query。

原因：事务需求异常。或许是业务逻辑类为注解为@Transactional

样例：

@Repository

@Transactional

public interface StudentServiceBean extends JpaRepository<Student,Long> {

@Query("select s from Student s where s.username=?1")

public Student find(String username);

@Modifying

@Query("update Student s set s.password=?1 where s.id=?2")

public int update(String password, Long id);

}