Question

我有很多表参考翻译表。为了区分与表或其他表相关的数据，我使用的是tableName列。我使用自定义SQL查询很长一段时间，但现在尝试迁移到JPA / Hibernate注释。

TranslationValue实体：

public class TranslationValue implements Serializable
{
    private Integer m_iKeyTranslation;
    private Integer m_iKeyLanguage;
    private String m_sTableName;
    private String m_sFieldName;
    private Integer m_iKeyRow;
    private String m_sValue;

    public void setKeyTranslation(Integer p_iKeyTranslation)
    {
        m_iKeyTranslation = p_iKeyTranslation;
    }

    @Id
    @GeneratedValue
    @Column(name = "keyTranslation")
    public Integer getKeyTranslation()
    {
        return m_iKeyTranslation;
    }

    public void setKeyLanguage(Integer p_iKeyLanguage)
    {
        m_iKeyLanguage = p_iKeyLanguage;
    }

    @Column(name = "keyLanguage")
    public Integer getKeyLanguage()
    {
        return m_iKeyLanguage;
    }

    public void setTableName(String p_sTableName)
    {
        m_sTableName = p_sTableName;
    }

    @Column(name = "tableName")
    public String getTableName()
    {
        return m_sTableName;
    }

    public void setFieldName(String p_sFieldName)
    {
        m_sFieldName = p_sFieldName;
    }

    @Column(name = "fieldName")
    public String getFieldName()
    {
        return m_sFieldName;
    }

    public void setKeyRow(Integer p_iKeyRow)
    {
        m_iKeyRow = p_iKeyRow;
    }

    @Column(name = "keyRow")
    public Integer getKeyRow()
    {
        return m_iKeyRow;
    }

    public void setValue(String p_sValue)
    {
        m_sValue = p_sValue;
    }

    @Column(name = "value")
    public String getValue()
    {
        return m_sValue;
    }
}

典型参考：

@OneToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL)
@JoinColumns({
    @JoinColumn(name="keyRow", referencedColumnName="keyPostCustomValue"),
    @JoinColumn(name="tableName", referencedColumnName="'constant'")
})
public List<TranslationValue> getValues()
{
    return m_lValues;
}

public void setValues(List<TranslationValue> p_lValues)
{
    m_lValues = p_lValues;
}

现在想知道是否有办法强制列tableName在注释中有一些字符串常量（在插入/更新子节点时将设置为常量，在获取时进行过滤）。我目前收到此错误：

org.hibernate.MappingException: Unable to find column with logical name: 'constant' in common_posts_customs_values_text

如果可能，我不想使用多个实体。

Answer 1

最后我稍微更改了设计并在Entity中添加了一个需要多语言内容示例的ID：

@ManyToOne(cascade = CascadeType.ALL)
@JoinColumn(name = "keyTitle")
public MultilingualText getTitle()
{
    return m_oTitle;
}

现在使用标准Entity用于多语言文字，不再需要tableName列来区分任何内容：

@Entity
@Table(name = "common_multilingualtexts")
public class MultilingualText implements Serializable
{
    private Integer m_iKeyMultilingualText;
    private Map<String, String> m_lValues = new HashMap<String, String>();

    public void setKeyMultilingualText(Integer p_iKeyMultilingualText)
    {
        m_iKeyMultilingualText = p_iKeyMultilingualText;
    }

    @Id
    @GeneratedValue
    @Column(name = "keyMultilingualText")
    public Integer getKeyMultilingualText()
    {
        return m_iKeyMultilingualText;
    }

    public void setValues(Map<String, String> p_lValues)
    {
        m_lValues = p_lValues;
    }

    @ElementCollection(fetch = FetchType.EAGER)
    @MapKeyColumn(name = "languageCode")
    @CollectionTable(name = "common_multilingualtexts_values", joinColumns = @JoinColumn(name = "keyMultilingualText"))
    @Column(name = "value")
    public Map<String, String> getValues()
    {
        return m_lValues;
    }

    public void put(String p_sLanguageCode, String p_sValue)
    {
        m_lValues.put(p_sLanguageCode,p_sValue);
    }

    public String get(String p_sLanguageCode)
    {
        if(m_lValues.containsKey(p_sLanguageCode))
        {
            return m_lValues.get(p_sLanguageCode);
        }

        return null;
    }
}

它只需要两个表来实现魔术：

CREATE TABLE `common_multilingualtexts` (
  `keyMultilingualText` int(11) NOT NULL auto_increment,
  PRIMARY KEY  (`keyMultilingualText`)
) ENGINE=MyISAM AUTO_INCREMENT=0 DEFAULT CHARSET=utf8;

CREATE TABLE `common_multilingualtexts_values` (
  `languageCode` varchar(5) NOT NULL,
  `keyMultilingualText` int(11) NOT NULL,
  `value` text,
  PRIMARY KEY  (`languageCode`,`keyMultilingualText`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8;

希望它会帮助别人！

OneToMany和常量JoinColumn可能吗？

1 个答案: