转自：https://blog.csdn.net/lzx925060109/article/details/40323741
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);
}