jpa

问题 I'm using Spring Framework and JPA to insert beans into my database. I need to insert almost 8000 entities, and this can delay too much. Why should I disable "second level cache" in Hibernate hibernate.cache.use_second_level_cache false When I set a "hibernate.jdbc.batch_size 20" in Hibernate, will it insert my beans like this? INSERT INTO VALUES (1),(2),(3)...(20); INSERT INTO VALUES (21),(2),(3)...(40); The documentation says: "Hibernate disables insert batching at the JDBC level

问题 I have a requirement in SpringBoot JPA service where the primary key value of the column must be stored in another column of same entity. In example below, rowId is generated by StringPrefixedLineSequenceIdGenerator . Whatever value it generates, I need to store the same in lineId column. @Entity @Table(name="CX_LINE") public class CXLine { @Id @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "cx_line_seq") @GenericGenerator( name = "cx_line_seq", strategy = "com.tmo.chub

问题 I am new to EJB, creating an application for fun/learning EJB following is the code. @Entity @Table(name = "PERSON", schema = "experiment") @NamedQuery(name = "Person.fetchAllPerson" , query = "select p from Person p") public class Person implements Serializable { private static final long serialVersionUID = 1L; @Id @GeneratedValue(strategy = GenerationType.AUTO) @Column(name = "id") private Long id; @Column(name = "name", length = 500) private String name; @Column(name = "age") private

问题 I am trying to create the follow structure using Hibernate with annotations: To create a ManyToMany relationship I had created two classes called SessionRiu and SessionRiuId (pk). This way the Session class has two foreign keys (agend_id and user_id) but when I try to create the OneToMany from operation the hibernate does not create the foreign using the id from session: Session FKs: Operation FKs ( empty ): As I am beginner in java and hibernate, I would appreciate any suggest about my code.

问题 This question already has answers here : Closed 8 years ago . Possible Duplicate: JPA OneToOne and ManyToMany between two entities I've searched for a solution to no avail. My question is I have two entities "Employee" and "Department" Many Employees belongs to One Department And One Department is headed by One Employee. Am getting errors anytime introduce both the @OneToOne and @OneToMany. This is the code public class Department { @Required public String deptName; @OneToMany(mappedBy="dept"

问题 I need to map a OneToMany relationship in hibernate, with the JPA annotations, in which is involved a weak entity. For example Table orders: CREATE TABLE orders( idorder serial NOT NULL, note varchar(30), CONSTRAINT orders_pkey PRIMARY KEY (idorder) ) Table OrderItems: CREATE TABLE orderitems( idorder integer NOT NULL, iditem serial NOT NULL, qnt integer, CONSTRAINT orderitems_pk PRIMARY KEY (idorder, iditem), CONSTRAINT fk_orderitems FOREIGN KEY (idorder) REFERENCES orders (idorder) MATCH

问题 I am trying to use LocalDate in my entities and this usage has plenty of documentation around the net. Which is why I am baffled it doesn't work. Here is my error: com.mysql.jdbc.MysqlDataTruncation: Data truncation: Incorrect date value: '\xAC\xED\x00\x05sr\x00\x0Djava.time.Ser\x95]\x84\xBA\x1B"H\xB2\x0C\x00\x00xpw\x07\x03\x00\x00\x07\xD7\x0C\x03x' So, it obviously needs a converter. I have tried the following links: This one says to add the spring converters to the scan path for the

问题 I am using Spring Boot and Spring Data JPA and Hibernate as the persistence provider. I have extended my Repository interface with JPARepository . I have a list of Entity Bean for a table. Some of them already exist and some of them not. I want to know what will happen when I call saveAll from my service layer and pass this List ? 回答1: If you look at the SimpleJpaRepository which is a common implementation of the CrudRepository you can see that it will simply invoke save for each of the

问题 I have some JPA annotated fields declared final like this: @Column(name = "SOME_FIELD", updatable = false, nullable = false) private final String someField; Those fields are stored in the database when the entity is inserted in the database. They cannot further be updated. For the Java programming language, such fields can be considered final. With the EclipseLink static weaving plugin, it's possible to lazy load entities, owing to some byte code instrumentation. I don't know if such

问题 I am using: Hibernate 4.3.5 Spring JPA 1.6.0 Javax Persistence API 2.1 The "refcodemailing" column is defined as an array of int: int[] My entity object: @Entity @Table public class CalendarEvent implements Serializable { @Id @GeneratedValue(strategy = GenerationType.AUTO) private int id = 0; @Convert(converter = IntegerArrayConverter.class) @Column(name = "refcodemailing") private final List<Integer> mailingCodes = new ArrayList<>(); // .... } I am trying to filter the column array with the