Let's take a look at very simple example, we have Person entity:
@Entity
@Table(name = "PERSONS")
public class Person implements Serializable {
private String firstName;
private Long id;
private Person spouse;
@Column(name = "FIRST_NAME")
public String getFirstName() {
return firstName;
}
@Id
public Long getId() {
return id;
}
@OneToOne(optional = true)
@JoinColumn(name = "SPOUSE_ID")
public Person getSpouse() {
return spouse;
}
...
}Suppose that PERSONS table has following entries:
| ID | SPOUSE_ID | FIRST_NAME |
| 1 | NULL | John |
| 2 | NULL | Mary |
| 3 | 4 | Adam |
| 4 | 3 | Eva |
We will build and execute very simple JPQL query:
Query query = entityManager.createQuery(
"select person from Person person where person.spouse.firstName = 'Eva' or 1 = 1");
Assert.assertEquals("Result list is too small,", 4, query.getResultList().size());
EclipseLink (2.2.0) converts our JPQL query into following SQL query:
SELECT t1.ID, t1.FIRST_NAME, t1.SPOUSE_ID
FROM PERSONS t0, PERSONS t1
WHERE (((t0.FIRST_NAME = 'Eva') OR (1 = 1)) AND (t0.ID = t1.SPOUSE_ID))java.lang.AssertionError: Result list too small, expected:<4> but was:<2>small select person0_.id as id1_, person0_.FIRST_NAME as FIRST2_1_, person0_.SPOUSE_ID as SPOUSE3_1_
from PERSONS person0_, PERSONS person1_
where person0_.SPOUSE_ID=person1_.id and (person1_.FIRST_NAME='Eva' or 1=1)Only OpenJPA (2.1.0) uses SQL expected by us:
SELECT t0.id, t0.FIRST_NAME, t1.id, t1.FIRST_NAME
FROM PERSONS t0
LEFT OUTER JOIN PERSONS t1 ON t0.SPOUSE_ID = t1.id
WHERE (t1.FIRST_NAME = 'Eva' OR 1 = 1)
select person
from Person person
left join person.spouse spouse
where spouse.firstName = 'Eva' or 1 = 1Now JPQL query returns all 4 records regardless of used JPA Provider.
