In this Tutorial, We will discuss about hibernate query, In this example we create a Query instance and implement the createQuery method for creating query String. In This example we delete the record from the table according to the HQL command.
Here is the simple Example code files.
CriteriaDeleteExample.java
package roseindia;
import org.hibernate.HibernateException;
import org.hibernate.Query;
import org.hibernate.Session;
import roseindia.util.HibernateUtil;
public class CriteriaDeleteExample {
public static void main(String[] args) {
Session session = HibernateUtil.getSessionFactory().openSession();
try {
String hql = "delete from User where UserName = :name";
Query query = session.createQuery(hql);
query.setString("name", "User 9");
int rowCount = query.executeUpdate();
System.out.println("Rows affected: " + rowCount);
} catch (HibernateException e) {
e.printStackTrace();
} finally {
session.close();
}
}
}
The bean class is as follows.
package roseindia.bean;
import java.util.Date;
public class User implements java.io.Serializable {
private static final long serialVersionUID = 1L;
private long Id = 0;
private int UserId = 0;
private String UserName = null;
private String UserAddr = null;
private String UserPhone = null;
private String UserEmail = null;
private Date UserDOB = null;
private int expInMonth = 0;
private double UserIncome = 0.0;
public User() {
}
public User(int UserId, String UserName, String UserAddr, String UserPhone,
String UserEmail, Date UserDOB, int expInMonth, double UserIncome) {
this.UserId = UserId;
this.UserName = UserName;
this.UserAddr = UserAddr;
this.UserPhone = UserPhone;
this.UserEmail = UserEmail;
this.UserDOB = UserDOB;
this.expInMonth = expInMonth;
this.UserIncome = UserIncome;
}
public long getId() {
return Id;
}
public void setId(long id) {
Id = id;
}
public int getUserId() {
return UserId;
}
public void setUserId(int userId) {
UserId = userId;
}
public String getUserName() {
return UserName;
}
public void setUserName(String userName) {
UserName = userName;
}
public String getUserAddr() {
return UserAddr;
}
public void setUserAddr(String userAddr) {
UserAddr = userAddr;
}
public String getUserPhone() {
return UserPhone;
}
public void setUserPhone(String userPhone) {
UserPhone = userPhone;
}
public String getUserEmail() {
return UserEmail;
}
public void setUserEmail(String userEmail) {
UserEmail = userEmail;
}
public Date getUserDOB() {
return UserDOB;
}
public void setUserDOB(Date userDOB) {
UserDOB = userDOB;
}
public int getExpInMonth() {
return expInMonth;
}
public void setExpInMonth(int expInMonth) {
this.expInMonth = expInMonth;
}
public double getUserIncome() {
return UserIncome;
}
public void setUserIncome(double userIncome) {
UserIncome = userIncome;
}
@Override
public String toString() {
return "User [UserAddr=" + UserAddr + ", UserDOB=" + UserDOB
+ ", UserEmail=" + UserEmail + ", UserId=" + UserId
+ ", UserName=" + UserName + ", UserPhone=" + UserPhone
+ ", UserSalary=" + UserIncome + ", expInMonth=" + expInMonth+ "]";
}
}
We use the following code to insert the values in the database table using mapping file.
DataInsert.java
package roseindia;
import java.util.Date;
import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.Transaction;
import roseindia.bean.User;
import roseindia.util.HibernateUtil;
public class DataInsert {
public static void main(String[] args) {
Session session = HibernateUtil.getSessionFactory().openSession();
Transaction transaction = null;
User user = null;
try {
transaction = session.beginTransaction();
for (int i = 0; i < 10; i++) {
user = new User(1 * i, "User " + i, "NEW DELHI" + i,
"999999458" + i, "[email protected]" + i, new Date(),
12 * i, 25000.00 * i);
session.save(user);
}
transaction.commit();
} catch (HibernateException e) {
transaction.rollback();
e.printStackTrace();
} finally {
session.close();
}
}
}
The database table mapping is in the file User.hbm.xml and hibernate configuration file is hibernate.cfg.xml.
hibernate.cfg.xml
<?xml version='1.0' encoding='utf-8'?> <!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd"> <hibernate-configuration> <session-factory> <!-- Database connection settings --> <property name="connection.driver_class">com.mysql.jdbc.Driver</property> <property name="connection.url">jdbc:mysql://localhost:3306/test</property> <property name="connection.username">root</property> <property name="connection.password"></property> <!-- JDBC connection pool (use the built-in) --> <property name="connection.pool_size">10</property> <!-- SQL dialect --> <property name="dialect">org.hibernate.dialect.MySQLDialect</property> <!-- Enable Hibernate's automatic session context management --> <property name="current_session_context_class">thread</property> <!-- Disable the second-level cache --> <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property> <!-- Echo all executed SQL to stdout --> <property name="show_sql">true</property> <!-- Drop and re-create the database schema on startup --> <property name="hbm2ddl.auto">update</property> <mapping resource="roseindia/bean/User.hbm.xml" /> </session-factory> </hibernate-configuration>
The User.hbm.xml file is as follows-
<?xml version="1.0"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> <hibernate-mapping> <class name="roseindia.bean.User" table="UserData"> <id name="Id" type="long" column="ID"> <generator class="native" /> </id> <property name="UserId" type="int" length="100" not-null="false" column="USER_ID" /> <property name="UserName" type="java.lang.String" length="100" not-null="false" column="USER_NAME" /> <property name="UserAddr" type="java.lang.String" length="100" not-null="false" column="USER_ADDR" /> <property name="UserPhone" type="java.lang.String" length="100" not-null="false" column="USER_PHONE" /> <property name="UserEmail" type="java.lang.String" length="100" not-null="false" column="USER_EMAIL" /> <property name="UserDOB" type="java.util.Date" not-null="false" column="USER_DOB" /> <property name="expInMonth" type="int" not-null="false" column="EXP_IN_MONTH" /> <property name="UserIncome" type="double" not-null="false" column="USER_INCOME" /> </class> </hibernate-mapping>
The HibernateUtil.java is as follows, is used to get the SessionFactory object to open session.
package roseindia.util;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
public class HibernateUtil {
private static final SessionFactory sessionFactory;
static {
try {
sessionFactory = new Configuration().configure()
.buildSessionFactory();
} catch (Throwable ex) {
System.err.println("Initial SessionFactory creation failed." + ex);
throw new ExceptionInInitializerError(ex);
}
}
public static SessionFactory getSessionFactory() {
return sessionFactory;
}
}
This example give the output the values from the table according to the criteria defined.
The structure of the database table is as follows:
The resultant query generated by hibernate is as follows which produces the output as follows
Hibernate: delete from UserData where USER_NAME=? Rows affected: 1
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