Hibernate 5 Query By Example 添加条件

Question

所以，我使用的是最新的 Hibernate 5.x 版本。我正在尝试通过示例进行简单查询。

这是休眠实体class:

@SuppressWarnings("serial")
@Entity
@Table(name = "company")
public class CompanyEntity implements Serializable
{
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "company_id")
private long companyId;

// `account_enabled` varchar(15) NOT NULL,
@Column(name = "company_enabled", columnDefinition = "BIT")
private boolean companyEnabled;

@Column(name = "company_name")
private String companyName;

@Column(name = "company_address1")
private String address1;

@Column(name = "company_address2")
private String address2;

@Column(name = "company_city")
private String addressCity;

@Column(name = "company_state")
private String addressState;

@Column(name = "company_postal_code")
private String addressPostalCode;

@Column(name = "company_country")
private String addressCountry;

@Column(name = "company_phone")
private String phone;

@ManyToOne(fetch = FetchType.EAGER)
@JoinColumn(name = "company_parent")
private CompanyEntity parent;

@Column(name = "entered_by")
private long enteredBy;

@Column(name = "entered_date")
@Temporal(TemporalType.TIMESTAMP)
private Date enteredDate;

@Column(name = "edited_by")
private long editedBy;

@Column(name = "edited_date")
@Temporal(TemporalType.TIMESTAMP)
private Date editedDate;

... getters, setters, hashCode, equals, toString 
    as auto-generated by Eclipse
 ...'
}

下面是 Dao 中的示例查询：

@Override
public List<CompanyEntity> getCompanyEntityByExample(CompanyEntity exampleEntity)
{
    Criteria criteria = this.sessionFactory.getCurrentSession().createCriteria(CompanyEntity.class).add(Example.create(exampleEntity));

    List<CompanyEntity> companyEntityList = criteria.list();

    System.out.println("getCompanyEntityByExample: companyEntityList: size=" + companyEntityList.size());
    System.out.println("getCompanyEntityByExample: companyEntityList=" + companyEntityList);

    return companyEntityList;
}

这是对此进行测试的测试：

 @Test
public void testGetCompanyByExample()
{
    String addressCity = "Boston";
    CompanyEntity exampleEntity = new CompanyEntity();
    exampleEntity.setAddressCity(addressCity);
    List<CompanyEntity> companyList = companyDao.getCompanyEntityByExample(exampleEntity);
    assertNotNull(companyList);
    assertEquals(true, companyList.size() == 1);
}

我知道根据数据库记录，应该至少返回一条记录，但在这种情况下，我没有得到任何数据。

这是实际执行的查询：

select this_.company_id as company_1_1_1_, this_.company_address1 as company_2_1_1_, this_.company_address2 as company_3_1_1_, this_.company_city as company_4_1_1_, this_.company_country as company_5_1_1_, this_.company_postal_code as company_6_1_1_, this_.company_state as company_7_1_1_, this_.company_enabled as company_8_1_1_, this_.company_name as company_9_1_1_, this_.edited_by as edited_10_1_1_, this_.edited_date as edited_11_1_1_, this_.entered_by as entered12_1_1_, this_.entered_date as entered13_1_1_, this_.company_parent as company15_1_1_, this_.company_phone as company14_1_1_, companyent2_.company_id as company_1_1_0_, companyent2_.company_address1 as company_2_1_0_, companyent2_.company_address2 as company_3_1_0_, companyent2_.company_city as company_4_1_0_, companyent2_.company_country as company_5_1_0_, companyent2_.company_postal_code as company_6_1_0_, companyent2_.company_state as company_7_1_0_, companyent2_.company_enabled as company_8_1_0_, companyent2_.company_name as company_9_1_0_, companyent2_.edited_by as edited_10_1_0_, companyent2_.edited_date as edited_11_1_0_, companyent2_.entered_by as entered12_1_0_, companyent2_.entered_date as entered13_1_0_, companyent2_.company_parent as company15_1_0_, companyent2_.company_phone as company14_1_0_ from company this_ left outer join company companyent2_ on this_.company_parent=companyent2_.company_id where (this_.company_city=? and this_.company_enabled=? and this_.edited_by=? and this_.entered_by=?)

如果您注意到 where 子句，它表示：

where (this_.company_city=? and this_.company_enabled=? and this_.edited_by=? and this_.entered_by=?)

应该只有：

where (this_.company_city=?)

所以，额外的标准打乱了我的查询，我无法获得正确的结果。

我想知道如何纠正和解决这个问题？我在Google上搜索了几次，来这里之前先查看了hibernate论坛。非常感谢任何帮助。

谢谢！

Answer 1

字段 company_enabled、edited_by 和 entered_by 是原语，所以它们在创建时有一个值，对于布尔值它是 false 并且长期它是 0。所以当创建对象时，值就在那里，当您调用过滤器时，hibernate 会看到字段值并将它们放在查询中。

Hibernate 5 Query By Example 添加条件

Hibernate 5 Query By Example adds criteria

java

mysql

hibernate

hibernate-criteria