JPQL query access google datastore [closed]

Question

My entity class :

public class ACCOUNT implements Serializable{

    private static final long serialVersionUID = 1L;

    @Id
    @Column(name = "USERNAME")
    private String Username;

    @Column(name = "PASSWORD")
    private String Password;

    public ACCOUNT(String user,String pass)
    {
        this.Username=user;
        this.Password=pass;
    }

    // geter and setter

my persistence.xml

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

<persistence-unit name="transactions-optional">
    <provider>org.datanucleus.api.jpa.PersistenceProviderImpl</provider>
    <class>com.materialshop.server.Datastore.ACCOUNT</class>
    <exclude-unlisted-classes/>
    <properties>
        <property name="datanucleus.NontransactionalRead" value="true"/>
        <property name="datanucleus.NontransactionalWrite" value="true"/>
        <property name="datanucleus.nontx.atomic" value="true"/>
        <property name="datanucleus.ConnectionURL" value="appengine"/>
    </properties>
</persistence-unit>
</persistence>

Now persist account and it was successful

ACCOUNT ac=new ACCOUNT("admin","123");
em.persist(ac);

I checked http://localhost:8888/_ah/admin and yes ,there is ACCOUNT entity with 1 record admin and 123 but when I use JPQL to get all entity , it returned null

Query q=new Query("SELECT ac FROM ACCOUNT ac");
List<ACCOUNT> list=q.getResultList();

even with em.find(ACCOUNT.class,"admin"); return null too

Did i miss something ? Please help me , very grateful for your help

Answer 1

I don't have experience with JPQL but this doesn't look like a proper SQL query:

Query q=new Query("SELECT ac FROM ACCOUNT ac");

It should either be:

SELECT * FROM ACCOUNT

or:

SELECT ac.* FROM ACCOUNT ac