Java Tutorial/JPA/Generated ID

Содержание

1 Create Table From Table Generator
2 Create Your Own Table For Table Generator
3 Generated Value Based On Sequence Generator
4 Generate ID From a Table
5 ID Generation Type: AUTO
6 ID Generation Type: IDENTITY
7 ID Generation Type: SEQUENCE
8 ID Generation Type: TABLE
9 JPA Create Sequence Table For You
10 Sequence Generator Name Init Value And Size
11 Use Sequence Generator

Create Table From Table Generator

File: Student.java

   <source lang="java">

import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.TableGenerator; @Entity public class Student {

 @TableGenerator(name = "Address_Gen", table = "ID_GEN", pkColumnName = "GEN_NAME", valueColumnName = "GEN_VAL", pkColumnValue = "Addr_Gen", initialValue = 10000, allocationSize = 100)
 @Id
 @GeneratedValue(strategy = GenerationType.TABLE, generator = "Address_Gen")
 private int id;
 transient private String name;
 public int getId() {
   return id;
 }
 public void setId(int id) {
   this.id = id;
 }
 public String getName() {
   return name;
 }
 public void setName(String name) {
   this.name = name;
 }
 public String toString() {
   return "\n\nID:" + id + "\nName:" + name + "\n\n";
 }

}</source>

Create Your Own Table For Table Generator

File: Student.java

   <source lang="java">

import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.TableGenerator; @Entity public class Student {

 @Id
 @TableGenerator(name = "EmpPkGen",
     table = "ID_GEN",
     pkColumnName = "GEN_NAME", 
     pkColumnValue = "Emp_Gen", 
     valueColumnName = "GEN_VAL", 
     initialValue = 0,
     allocationSize = 100
  )
 @GeneratedValue(strategy=GenerationType.TABLE)

/*create table id_gen (

   gen_name varchar(80),
   gen_val integer,
   constraint pk_id_gen
       primary key (gen_name)

);

/

 private int id;
 transient private String name;

 public int getId() {
   return id;
 }
 public void setId(int id) {
   this.id = id;
 }
 public String getName() {
   return name;
 }
 public void setName(String name) {
   this.name = name;
 }

 public String toString() {
   return "\n\nID:" + id + "\nName:" + name + "\n\n";
 }

}</source>

Generated Value Based On Sequence Generator

File: Student.java

   <source lang="java">

import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.Id; import javax.persistence.SequenceGenerator; @Entity public class Student {

 @SequenceGenerator(name="Emp_Gen", sequenceName="Emp_Seq")
 @Id @GeneratedValue(generator="Emp_Gen")
 private int id;
 private String name;

 public int getId() {
   return id;
 }
 public void setId(int id) {
   this.id = id;
 }
 public String getName() {
   return name;
 }
 public void setName(String name) {
   this.name = name;
 }

 public String toString() {
   return "\n\nID:" + id + "\nName:" + name + "\n\n";
 }

}</source>

Generate ID From a Table

File: Student.java

   <source lang="java">

import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.TableGenerator; @Entity public class Student {

 @TableGenerator(name = "Address_Gen", table = "ID_GEN", pkColumnName = "GEN_NAME", valueColumnName = "GEN_VAL", pkColumnValue = "Addr_Gen", initialValue = 10000, allocationSize = 100)
 @Id
 @GeneratedValue(strategy = GenerationType.TABLE, generator = "Address_Gen")
 private int id;
 transient private String name;
 public int getId() {
   return id;
 }
 public void setId(int id) {
   this.id = id;
 }
 public String getName() {
   return name;
 }
 public void setName(String name) {
   this.name = name;
 }
 public String toString() {
   return "\n\nID:" + id + "\nName:" + name + "\n\n";
 }

}</source>

ID Generation Type: AUTO

File: Helper.java

   <source lang="java">

import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.ResultSetMetaData; import java.sql.Statement; public class Helper {

 public static void checkData() throws Exception {
   Class.forName("org.hsqldb.jdbcDriver");
   Connection conn = DriverManager.getConnection("jdbc:hsqldb:data/tutorial", "sa", "");
   Statement st = conn.createStatement();
   ResultSet mrs = conn.getMetaData().getTables(null, null, null, new String[] { "TABLE" });
   while (mrs.next()) {
     String tableName = mrs.getString(3);
     System.out.println("\n\n\n\nTable Name: "+ tableName);
     ResultSet rs = st.executeQuery("select * from " + tableName);
     ResultSetMetaData metadata = rs.getMetaData();
     while (rs.next()) {
       System.out.println(" Row:");
       for (int i = 0; i < metadata.getColumnCount(); i++) {
         System.out.println("    Column Name: "+ metadata.getColumnLabel(i + 1)+ ",  ");
         System.out.println("    Column Type: "+ metadata.getColumnTypeName(i + 1)+ ":  ");
         Object value = rs.getObject(i + 1);
         System.out.println("    Column Value: "+value+"\n");
       }
     }
   }
 }

}</source>

ID Generation Type: IDENTITY

File: Main.java

   <source lang="java">

import java.sql.Timestamp; import java.util.List; import java.util.UUID; import javax.persistence.EntityManager; import javax.persistence.EntityManagerFactory; import javax.persistence.Persistence; import javax.persistence.Query; public class Main {

 static EntityManagerFactory emf = Persistence.createEntityManagerFactory("JPAService");
 static EntityManager em = emf.createEntityManager();
 public static void main(String[] a) throws Exception {
   em.getTransaction().begin();
   
   
   Student student = new Student();
   student.setName("Joe");
 
   
   em.persist(student);
   em.flush();
   em.getTransaction().rumit();
   
   Query query = em.createQuery("SELECT e FROM Student e");
   List<Student> list = (List<Student>) query.getResultList();
   System.out.println(list);
   
   
   em.close();
   emf.close();
   
   Helper.checkData();
 }

}</source>

ID Generation Type: SEQUENCE

File: Main.java

   <source lang="java">

import java.sql.Timestamp; import java.util.List; import java.util.UUID; import javax.persistence.EntityManager; import javax.persistence.EntityManagerFactory; import javax.persistence.Persistence; import javax.persistence.Query; public class Main {

 static EntityManagerFactory emf = Persistence.createEntityManagerFactory("JPAService");
 static EntityManager em = emf.createEntityManager();
 public static void main(String[] a) throws Exception {
   em.getTransaction().begin();
   
   
   Student student = new Student();
   student.setName("Joe");
 
   
   em.persist(student);
   em.flush();
   em.getTransaction().rumit();
   
   Query query = em.createQuery("SELECT e FROM Student e");
   List<Student> list = (List<Student>) query.getResultList();
   System.out.println(list);
   
   
   em.close();
   emf.close();
   
   Helper.checkData();
 }

}</source>

ID Generation Type: TABLE

File: Helper.java

   <source lang="java">

import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.ResultSetMetaData; import java.sql.Statement; public class Helper {

 public static void checkData() throws Exception {
   Class.forName("org.hsqldb.jdbcDriver");
   Connection conn = DriverManager.getConnection("jdbc:hsqldb:data/tutorial", "sa", "");
   Statement st = conn.createStatement();
   ResultSet mrs = conn.getMetaData().getTables(null, null, null, new String[] { "TABLE" });
   while (mrs.next()) {
     String tableName = mrs.getString(3);
     System.out.println("\n\n\n\nTable Name: "+ tableName);
     ResultSet rs = st.executeQuery("select * from " + tableName);
     ResultSetMetaData metadata = rs.getMetaData();
     while (rs.next()) {
       System.out.println(" Row:");
       for (int i = 0; i < metadata.getColumnCount(); i++) {
         System.out.println("    Column Name: "+ metadata.getColumnLabel(i + 1)+ ",  ");
         System.out.println("    Column Type: "+ metadata.getColumnTypeName(i + 1)+ ":  ");
         Object value = rs.getObject(i + 1);
         System.out.println("    Column Value: "+value+"\n");
       }
     }
   }
 }

}</source>

JPA Create Sequence Table For You

File: Helper.java

   <source lang="java">

import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.ResultSetMetaData; import java.sql.Statement; public class Helper {

 public static void checkData() throws Exception {
   Class.forName("org.hsqldb.jdbcDriver");
   Connection conn = DriverManager.getConnection("jdbc:hsqldb:data/tutorial", "sa", "");
   Statement st = conn.createStatement();
   ResultSet mrs = conn.getMetaData().getTables(null, null, null, new String[] { "TABLE" });
   while (mrs.next()) {
     String tableName = mrs.getString(3);
     System.out.println("\n\n\n\nTable Name: "+ tableName);
     ResultSet rs = st.executeQuery("select * from " + tableName);
     ResultSetMetaData metadata = rs.getMetaData();
     while (rs.next()) {
       System.out.println(" Row:");
       for (int i = 0; i < metadata.getColumnCount(); i++) {
         System.out.println("    Column Name: "+ metadata.getColumnLabel(i + 1)+ ",  ");
         System.out.println("    Column Type: "+ metadata.getColumnTypeName(i + 1)+ ":  ");
         Object value = rs.getObject(i + 1);
         System.out.println("    Column Value: "+value+"\n");
       }
     }
   }
 }

}</source>

Sequence Generator Name Init Value And Size

File: Customer.java

   <source lang="java">

import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.Id; import javax.persistence.PostLoad; import javax.persistence.PostPersist; import javax.persistence.PostRemove; import javax.persistence.PostUpdate; import javax.persistence.PrePersist; import javax.persistence.PreRemove; import javax.persistence.PreUpdate; import javax.persistence.SequenceGenerator; @Entity @SequenceGenerator(name = "SequenceIdGenerator",

   sequenceName = "SEQ_ID_GEN", initialValue = 100, 
   allocationSize = 20)

public class Customer implements java.io.Serializable {

 @Id
 @GeneratedValue(generator = "SequenceIdGenerator")
 private int id;
 private String lastName;
 private String firstName;

 public int getId() {
   return id;
 }
 public void setId(int pk) {
   id = pk;
 }
 public String getLastName() {
   return lastName;
 }
 public void setLastName(String lastName) {
   this.lastName = lastName;
 }
 public String getFirstName() {
   return firstName;
 }
 public void setFirstName(String firstName) {
   this.firstName = firstName;
 }
 @PrePersist
 public void prePersist() {
   System.out.println("@PrePersist");
 }
 @PostPersist
 public void postPersist() {
   System.out.println("@PostPersist");
 }
 @PostLoad
 public void postLoad() {
   System.out.println("@PostLoad");
 }
 @PreUpdate
 public void preUpdate() {
   System.out.println("@PreUpdate");
 }
 @PostUpdate
 public void postUpdate() {
   System.out.println("@PostUpdate");
 }
 @PreRemove
 public void preRemove() {
   System.out.println("@PreRemove");
 }
 @PostRemove
 public void postRemove() {
   System.out.println("@PostRemove");
 }

}</source>

Use Sequence Generator

File: Student.java

   <source lang="java">

import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.Id; import javax.persistence.SequenceGenerator; @Entity public class Student {

 @SequenceGenerator(name="Emp_Gen", sequenceName="Emp_Seq")
 @Id @GeneratedValue(generator="Emp_Gen")
 private int id;
 private String name;

 public int getId() {
   return id;
 }
 public void setId(int id) {
   this.id = id;
 }
 public String getName() {
   return name;
 }
 public void setName(String name) {
   this.name = name;
 }

 public String toString() {
   return "\n\nID:" + id + "\nName:" + name + "\n\n";
 }

}</source>

Java Tutorial/JPA/Generated ID

Содержание

Create Table From Table Generator

Create Your Own Table For Table Generator

Generated Value Based On Sequence Generator

Generate ID From a Table

ID Generation Type: AUTO

ID Generation Type: IDENTITY

ID Generation Type: SEQUENCE

ID Generation Type: TABLE

JPA Create Sequence Table For You

Sequence Generator Name Init Value And Size

Use Sequence Generator

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