Why is deleting an entity that doesn't exist succeeding?

[Dave Alvarado]

Hi,

I'm using JPA 2.0, Hibernate 4.1.0.Final, Spring 3.1.1.RELEASE, and JUnit 4.8.1. I'm confused about why a JUnit test is NOT failing. I have this test

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration({ "classpath:test-context.xml" })
public class ProductDaoTest extends AbstractTransactionalJUnit4SpringContextTests 
{

    ...
    @Test
    public void testDeleteWithNonexistentEntity()
    {
        final String id = m_testProps.getProperty("test.product.id");
        Product product = m_productDao.findById(id);
        Assert.assertNotNull("A pre-condition of this test is that a product exist with id \"" + id + "\".", product);        
        m_productDao.delete(product);
        // Now try and delete it again.
        m_productDao.delete(product);
        entityManager.flush();
    }   // testDeleteWithNonexistentEntity

My code for deleting an entity is

    protected boolean delete(Object obj)
    {
        boolean ret = false;
        if (obj != null)
        {
            m_entityManager.remove(obj);
            ret = true;
        }   // if
        return ret;
    }

Shouldn't the second call to "delete" result in some kind of exception since the entity was removed in the first call? My flush mode is set to AUTO (the default) and below is how I configure my entity manager in my JUnit Spring application context and persistence.xml. Why isn't the second delete call failing?

<?xml version="1.0" encoding="UTF-8"?>

<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
	xmlns:p="http://www.springframework.org/schema/p"
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:mvc="http://www.springframework.org/schema/mvc" 
	xmlns:util="http://www.springframework.org/schema/util"
	xmlns:tx="http://www.springframework.org/schema/tx" 
	xmlns:jdbc="http://www.springframework.org/schema/jdbc"
	xmlns:jaxws="http://cxf.apache.org/jaxws"
	xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.1.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-3.1.xsd
http://www.springframework.org/schema/util
http://www.springframework.org/schema/util/spring-util-3.1.xsd
http://www.springframework.org/schema/tx
                        http://www.springframework.org/schema/tx/spring-tx-3.1.xsd
                        http://www.springframework.org/schema/jdbc 
                        http://www.springframework.org/schema/jdbc/spring-jdbc-3.1.xsd
                        http://cxf.apache.org/jaxws 
                        http://cxf.apache.org/schemas/jaxws.xsd">

	<!-- Enable annotation driven controllers, validation etc... -->
	<mvc:annotation-driven />

	<context:component-scan base-package="org.mainco" />

	<!-- Define test properties -->
	<util:properties id="applicationProperties" location="classpath:test.properties" />

	<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="org.hsqldb.jdbcDriver"/>
        <property name="url" value="jdbc:hsqldb:mem:lycea" />
        <property name="username" value="sa" />
        <property name="password" value="" />
    </bean>
    
	<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
        <property name="jpaVendorAdapter">
            <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter"/>
        </property>
        <property name="persistenceXmlLocation" value="classpath:META-INF/test-persistence.xml"/>
        <property name="persistenceUnitName" value="orgTestingDatabase"/>
        <property name="dataSource" ref="dataSource"/>
    </bean>

	<bean id="sharedEntityManager" class="org.springframework.orm.jpa.support.SharedEntityManagerBean">
       <property name="entityManagerFactory" ref="entityManagerFactory"/>
    </bean>

	<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
        <property name="entityManagerFactory" ref="entityManagerFactory"/>
    </bean>

	<tx:annotation-driven />

	<jdbc:embedded-database id="embedded" type="HSQL"/> 
	<jdbc:initialize-database data-source="dataSource">
		<jdbc:script location="classpath:db-test-data.sql"/>	
	</jdbc:initialize-database>
	
</beans>

and here is the persistence.xml file

<persistence version="2.0"
	xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://java.sun.com/xml/ns/persistence
        http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd">
	<persistence-unit name="orgTestingDatabase" transaction-type="RESOURCE_LOCAL">
		<provider>org.hibernate.ejb.HibernatePersistence</provider>
		<shared-cache-mode>ENABLE_SELECTIVE</shared-cache-mode>
		<properties>
			<property name="hibernate.ejb.cfgfile" value="/hsql_hibernate.cfg.xml" />
		</properties>
	</persistence-unit>
</persistence>

[Salil Vverma]

Hey Dave,

why should it fail ?
In RDBMS, if you try to delete an non-existing entry from database using sql, database does not throw any exception/error. The statement succeeds with message that zero records impacted. Hibernate provides just a layer on top of database and does not create new behaviors