title: Spring Boot JPA Query with is empty and is null key words
body: <p>I'm using spring boot version 2.0.3.RELEASE and spring data jpa version 2.0.8.RELEASE. I have two tables TableA, TableB and they are one to one mapped.</p>
  
  <p>TableA</p>
  
  <pre><code>@Entity
  @Table(name = "table_a")
  public class TableA {
  
       @Id
       @Column(name = "id")
       private Long id;
  
       @OneToOne(mappedBy = "table_b", cascade = CascadeType.ALL)
       private TableB tableB;
  }
  </code></pre>
  
  <p>TableB</p>
  
  <pre><code>@Entity
  @Table(name = "table_b")
  public class TableB {
  
       @Id
       @Column(name = "id")
       private Long id;
  
       @OneToOne
       @JoinColumn(name = "id")
       private TableA tableA;
  }
  </code></pre>
  
  <p>I need to get TableA values when the Mapped TableB is not existed. I wrote below query in TableA Jpa Repository.</p>
  
  <pre><code>@Query(value = "select a from TableA a where a.tableB is null and a.id=?1")
  TableA findTableAValues(Long id);
  </code></pre>
  
  <p>But it doesn't give the expected result. If I replaced the <strong>is null</strong> with the <strong>is empty</strong> key word, query gives the expected result. Please anyone can explain why this kind of thing is happened?</p>