JPA EntityManager deletes all records in the database

Question

I have one servlet that inserts into my database. This is working fine. The second servlet shows what the first one inserted, however whenever I start the servlet mapping, all records in all my tables are deleted! My JPA implementation is EclipseLink and db is MySQL.

Is it possible that the way to get EntityManagerFactory is causing db schema recovery?

EntityManagerFactory factory;
factory = Persistence.createEntityManagerFactory("gate");
EntityManager em = factory.createEntityManager();

List list;
try{
   Query query = em.createQuery("SELECT i from PersistentItem i");
   list= query.getResultList();

   System.out.println(list.size());

}finally{
        em.close();
    }

Map<String, Object> myModel = new HashMap<String, Object>();
myModel.put("title", "List of all items");
myModel.put("itemList", list);

return new ModelAndView("list", "model", myModel);

My persistence.xml:

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="1.0" 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_1_0.xsd">
<persistence-unit name="gate" transaction-type="RESOURCE_LOCAL">
    <description>Eclipselink</description>
    <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>

    <class>info.lenni.gate.persistence.PersistentItem</class>
    <exclude-unlisted-classes>false</exclude-unlisted-classes>
    <properties>
        <property name="eclipselink.jdbc.driver" value="com.mysql.jdbc.Driver" />
        <property name="eclipselink.jdbc.url" value="jdbc:mysql://localhost:3306/gate" />

        <property name="eclipselink.jdbc.user" value="root" />
        <property name="eclipselink.jdbc.password" value="" />

        <property name="eclipselink.ddl-generation" value="drop-and-create-tables" />
        <property name="eclipselink.ddl-generation.output-mode" value="database" />
        <property name="eclipselink.logging.level" value="OFF"/>
    </properties>
</persistence-unit>

Answer 1

This is exactly how you suspect. According to [EclipseLink docs] ( http://wiki.eclipse.org/Using_EclipseLink_JPA_Extensions_(ELUG)) String

  <property name="eclipselink.ddl-generation" value="drop-and-create-tables" />

EclipseLink .

create-tables.