I'm using Netbeans 8.1, Java EE 7, and MS SQL Server. The application does transactions that contain individual items stored in a separate table. I need the primary key txId to create the individual records that are linked with a Foreign Key.
Here is an excerpt from the entity:
public class Transactions implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Basic(optional = false)
#NotNull
#Column(name = "tx_id")
private Long txId;
//remainder left off for brevity
}
Here is an excerpt from the client:
public void create() {
persist(PersistAction.CREATE, "blah");
}
My major question is how can I get the Primary Key returned back from the persist() method?
Related
Here's my Reader :
private static final String SELECT_ALL_BOOKS = "SELECT * FROM BOOKS WHERE COLOR = 'yellow'";
#Bean
public JdbcCursorItemReader<BookEntity> itemReader(final DataSource dataSource) {
return new JdbcCursorItemReaderBuilder<BookEntity>()
.name("book_reader")
.sql(SELECT_ALL_BOOKS)
.dataSource(dataSource)
.rowMapper(new BeanPropertyRowMapper<>(BookEntity.class))
.build();
}
And my entity :
#Entity
#Getter
#Setter
#Table(name = "book")
#AllArgsConstructor
#NoArgsConstructor
public class BookEntity implements java.io.Serializable {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "id_book")
private Integer idBook;
#Column(name = "color")
private String color;
#Column(name = "page_number")
private Integer pageNumber;
#Column(name = "read")
private Boolean read;
#ManyToOne(fetch = FetchType.EAGER, cascade = {CascadeType.ALL})
#JoinColumn(name = "id_author")
private Author author;
...
...
}
Problem is : with my job executing my step, I'm having the books but with an author = null. So the foreign key is not mapped correctly, all the other String/Integer/Boolean fields are retrieved correctly.
I'm new with Spring batch so maybe I'm using a wrong kind of reader.
Any one has an idea about the problem ? Thanks
Please refer this- You are using JDBC Item reader that is mapped to native columns and properties are binded by BeanPropertyRowMapper
https://docs.spring.io/spring-batch/docs/current/reference/html/readersAndWriters.html#JdbcCursorItemReader
Change the query join with AUTHOR tables as a native query or use JPA readers to support ORM
Below reference will give repository reader
https://docs.spring.io/spring-batch/docs/current/api/org/springframework/batch/item/data/RepositoryItemReader.html
Below example give some idea to implement and its SO references
https://github.com/gpassini/Spring-Batch-RepositoryItemReader-NativeQuery-Example/tree/master/src/main
In spring boot JPA I tried to implement sequence generator but it is not working.
the following is my entity
#Entity
#Table(name = "role_level")
public class RoleLevel implements Serializable {
/**
*
*/
private static final long serialVersionUID = 1L;
#Id
#SequenceGenerator(name = "role_level_sequence", sequenceName = "role_level_id_seq",allocationSize = 1)
#GeneratedValue(strategy = GenerationType.SEQUENCE,generator = "role_level_sequence")
#Column(name = "id", updatable = false)
private Long id;
#Column(name = "role_level")
private String roleLevel;
#Column(name = "role_level_description")
private String roleLevelDescription;
//getters and setters
}
when I insert value in directly through the database then next sequence from the db is not getting in jpa.it shows
org.postgresql.util.PSQLException: ERROR: duplicate key value violates unique constraint "role_level_pkey"
Detail: Key (id)=(7) already exists.
But the console shows
Hibernate: select nextval ('role_level_id_seq')
I think its not working.
Is there any solution for this.?
In spring data jpa Application I created one model with #entity annotation. I am saving that model data into table. I am auto incrementing primary key. But when I am saving data into table it's not sequentially auto incrementing.
#GeneratedValue(strategy = GenerationType.AUTO)
class file
#Entity
#Table(name="exception")
public class Exception implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy = GenerationType.AUTO, generator = "exception_seq_generator")
#SequenceGenerator(name = "exception_seq_generator", sequenceName = "exception_seq")
#Column(name="exception_id")
public Integer exceptionId;
#Column(name="status_code")
public Integer statusCode;
public String message;
public String status;
public String error;
//Getter and setter
Table
can any one tell me why primary key is not auto incrementing sequentially? why it's not taking 2,3,4.....
First of all try setting the allocationSize:
#Id
#GeneratedValue(strategy = GenerationType.AUTO, generator = "exception_seq_generator")
#SequenceGenerator(name = "exception_seq_generator", sequenceName = "exception_seq", allocationSize=1)
#Column(name="exception_id")
public Integer exceptionId;
Also check your current Sequence in the Database, it might have a wrong value now.
Simpler aproach:
Define the primary-key column in PostgreSQL DB as SERIAL:
CREATE TABLE xy (
id SERIAL PRIMARY KEY;
);
And annotate the Column with:
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
The SERIAL type, creates an auto-increment sequence for you and you don't have that much overhead in you JPA Entities.
I'm trying to delete the parent student or parent course and I get this error:
Caused by: org.postgresql.util.PSQLException: ERROR: update or delete on table "student" violates foreign key constraint "fkeyvuofq5vwdylcf78jar3mxol" on table "registration"
RegistrationId class is a composite key used in Registration class. I'm using Spring data jpa and spring boot.
What am I doing wrong? I know that putting cascadetype.all should also remove the children when the parent is deleted but it is giving me an error instead.
#Embeddable
public class RegistrationId implements Serializable {
#JsonIgnoreProperties("notifications")
#OneToOne(cascade=CascadeType.ALL)
#JoinColumn(name = "student_pcn", referencedColumnName="pcn")
private Student student;
#JsonIgnoreProperties({"teachers", "states", "reviews"})
#OneToOne(cascade=CascadeType.ALL)
#JoinColumn(name = "course_code", referencedColumnName="code")
private Course course;
Registration class
#Entity(name = "Registration")
#Table(name = "registration")
public class Registration {
#EmbeddedId
private RegistrationId id;
When you're using a relational DB, you are setting entities with relationships between these entities.
The error that you're getting means that:
You're trying to delete a record that its primary key is functioning as a foreign key in another table, thus you can't delete it.
In order to delete that record, first, delete the record with the foreign key, and then delete the original that you wanted to delete.
I made it work by using hibernate #OnDelete annotation. Some how the JPA.persistence CascadeTypes were not working. They had no effect for whichever I chose.
Just like below. Now I can remove the parent Student or the parent Course and all children(Registrations) are deleted with them.
#Embeddable
public class RegistrationId implements Serializable {
#JsonIgnoreProperties("notifications")
#OnDelete(action = OnDeleteAction.CASCADE)
#OneToOne
#JoinColumn(name = "student_pcn", referencedColumnName="pcn")
private Student student;
#JsonIgnoreProperties({"teachers", "states", "reviews"})
#OnDelete(action = OnDeleteAction.CASCADE)
#OneToOne
#JoinColumn(name = "course_code", referencedColumnName="code")
private Course course;
Foreign keys guarantee that an entry will exist in another table. This is a way of ensuring data integrity. SQL will never allow you to delete this entry while it still deletes in the other table. Either (1) this is letting you know you would have made a grave mistake by deleting this thing which is required or (2) you would like to put in a cascading delete so that not only is this entry deleted but so is what is supposed to be referencing it in the other table. Information on cascading deletes can be found here and written fairly easily (https://www.techonthenet.com/sql_server/foreign_keys/foreign_delete.php). If neither of these two descriptions fits you, evaluate why your foreign key relationship exists in the first place because it probably should not.
Try this method too. I got the answer with this method,This is just a test to remove.
Pay attention to the cascade!
MyUser Entity
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private String firstname;
private String lastname;
private String mobile;
#Column(unique = true)
private String email;
private Long date;
private LocalTime localiime;
private LocalTime localiimeend;
#ManyToOne(fetch = FetchType.LAZY,cascade = CascadeType.MERGE)
#JoinColumn(foreignKey = #ForeignKey(name = "role_fk"))
private Role role;
Role Entity
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private String name;
private String description;
#OneToMany(mappedBy = "role", fetch = FetchType.LAZY, cascade = CascadeType.ALL)
private List<MyUser> users;
#ManyToOne (fetch = FetchType.LAZY,cascade = CascadeType.MERGE)
#JoinColumn(foreignKey = #ForeignKey(name = "rolecat_fk"))
private rolecat rolecat;
rolecat Entity
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private String name;
#OneToMany(mappedBy = "rolecat", fetch = FetchType.LAZY, cascade = CascadeType.ALL)
private List<Role> roles;
I am bit beginner on JPA and need some help on fetching the Many to One relationship in JPA.
I have below entities.
User which stores all user information . User extends Audiatable abstract class which is for holding auidt paramters like last modified date, creation date etc.
I am trying to add another fields as lastUpdatedByUser which should get fetched from lastUpdatedBy for which I amtrying to add Many-One relationship.
But the relation is not working somehow, am I doing something wrong here?
AuditableEntity.java
public abstract class AuditableEntity<T extends Entity<T, ID>, ID> implements Auditable {
private static final long serialVersionUID = 1L;
#Column(name = "cruserid")
private Long createdBy;
#Column(name = "crdate")
#Type(type = JpaConstants.TYPE_LOCAL_DATE_TIME)
private LocalDateTime createdOn;
#Column(name = "chuserid")
private Long lastUpdatedBy;
#Column(name = "chdate")
#Type(type = JpaConstants.TYPE_LOCAL_DATE_TIME)
private LocalDateTime lastUpdatedOn;
#Transient
#ManyToOne(fetch = FetchType.LAZY, targetEntity = User.class)
#JoinColumn(name = "usrId", referencedColumnName = "chuserid")
private User lastUpdatedByUser;
User.java
public class User extends AuditableEntity<User, Long> {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "usrId")
private Long id;
#Column(name = "usrName")
private String name;
#Column(name = "loginame")
private String loginName;
}
Well, you marked the association with #Transient, which means that the field is not persistent and should be ignored by JPA.
And you also seem to have two different fields to store the same information: lastUpdatedBy and lastUpdateByUser. Remove the first one, and map the second one as
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "chuserid")
private User lastUpdatedByUser;
This tells that the association is a ManyToOne to the User entity (no need to specify the targetEntity since it's the type of the field), and that this association is materialized by the join column named "chuserid", in the auditable entity's table, and referencing the ID of the User entity (referencedColumnName is only useful when you use composite IDs, or when you reference an entity by a column which is the the ID)