UPDATE is called when only SELECT is expected

[Sergej Shafarenka]

Hey Guys!

I use OpenJPA in tandem with SpringFramework. I wrote a simple application 
which reads some data from MySQL database and faced very weird problem: openjpa 
executes an "update" statement when only "select" query is used and no object 
modifications are done. 

// My service's method looks like this one
@Transactional(readOnly=true)
public void test(String user) {
        Query query = m_entityManager.createQuery("select u from User u");
        List<User> users = (List<User>) query.getResultList();
        for (User u : users) {
                if (u.getLoginName().equals(user)) {
                        System.out.println("Bingo!");
                }
        }
}

// User class is very simple
@Entity
@Table(name="user")
public class User implements Serializable {
        @Id
        @Column(name="user_id")
        private int m_id;

        @Column(name="user_login_name")
        private String m_loginName;

        // getters and setters are omitted as not essential for problem 
understanding
}

// and openjpa's log-output looks like the one below
openjpa.jdbc.SQL - <t 6533862, conn 16102116> executing prepstmnt 16900472 
SELECT t0.user_id, t0.user_login_name from t0
openjpa.jdbc.SQL - <t 6533862, conn 16102116> [0 ms] spent
// and this is the problem :(((
openjpa.jdbc.SQL - <t 6533862, conn 16102116> executing prepstmnt 25980092 
UPDATE user SET user_login_name = ? WHERE user_id = ? [params=(String) test, 
(int) 1] 
openjpa.jdbc.SQL - <t 6533862, conn 16102116> [0 ms] spent


It is already three days I spent on fixing the problem with no success :( Would 
someone help me please. I am even ready to switch off automatic update 
functionality if there were such possibility.

Thanks and best regards,
Sergej