examples of using wrapper classes on the hibernate official website, public class PersonWrapper { private final Long id; private final String nickName; public PersonWrapper(Long id, String nickName) { this.id = id; this.n...

1. Recently, when I was learning hibernate, a question suddenly occurred to me: can I use hibernate instead of a database to store data? Can it cooperate with hibernate with simple file access? 2. In order to answer this question, I think we should fi...

https: github.com thymeleaf . I use jpa, to cascade the two classes through annotations. in the html page, when you get the object of any class through the thymeleaf tag, it will appear . java.lang.StackOverflowError: null at sun.reflect.misc.Refl...

cascading deletions are actually performed but in practice, it is this kind of pseudo deletion that creates flag and assigns 0,1 . is there a callback method that can handle the logic of deletion? Only in this way can we write custom delete logic h...

one class @Entity public class Shuo{ @Id @GeneratedValue private int id; private String title; private Date date; String content; @ManyToOne(cascade = CascadeType.REFRESH) @JoinColumn(name = "user_id") private User user; : @OneT...

< H2 > description: < H2 > there are 19 pieces of data in total. When using PageRequest.of (page, limit) for paging query, as long as the limit parameter is greater than 19, it is found to be empty. less than 19:00, function is normal. < H2 > Test C...

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Hibernate lazily loads the acquired entity class, which has been handled by javaassit. Now there is no time to study javaassit, wants to know how to get the original Class, of the entity class and the original attribute of the entity class and the Class ...

session.save (c) converts instantaneous objects into persistent objects, but the c object does not have a primary key. A primary key generation strategy is configured in the configuration file. When native, executes session.save (c), an insert statement...

seniors, use SpringJPA for the first time. Now the entity class has a field that looks like this: private String movie_id; and I want to sort through this field. After inheriting PagingAndSortingRepository, the code is: Sort sort = new Sort(...

the test case cannot roll back the data and is inserted directly into the database? applicationContext.xml <context:annotation-config>< context:annotation-config> <!--dataSource--> <bean id="dataSource" class="org...

xml file related configuration and error prompt Cannot resolve symbol classpath:. : properties: the runtime environment is dependent on tomcat7, data validation: <dependency> <groupId>javax.validation< groupId> ...

mysql database Save the code as follows: : ...

the data found is a collection of the corresponding types of tables, which can be received. But when traversing, you will run out of ClassCaseException . ...

the original title was "springdata jpa uses @ ElementCollection to report an error " Table doesn t exists ". Later, I patiently read all the error messages and found that the source of the error was that the sql syntax generated by hibernate was inco...

I have an entity, for address and an entity, for Person, and he has an attribute address_ids; in it, which is an int [] type, which contains an array of address s id. how to map this address_ids field directly to an object of List < Address >. or i...

public class ScanRegisterBean implements Serializable{ @Min(value = 1) @Max(value = Long.MAX_VALUE) private long id; @NotBlank(groups = {ScanRegister.class, Register.class}) @Length(min = 2, max = 20,groups = {ScanRegister.class, Re...

I want to invert a value every time I update. Do I have to get this object through java, instead of writing sql ?...

in the interview the day before yesterday, the interviewer asked me how to do one-to-many mapping in hibernate, so I said how to configure it in the hbm file and add collection classes to entity classes as extended objects. In short, I answered the speci...

try { connection.setAutoCommit(false); bankDao.transferMoney(+2000, 1, connection); 1 2000 if(true){ throw new RuntimeException(); } bankDao.transferMoney(-2000, 2, connection); 2 2000 ...