java Hibernate参数注入内部映射，可能吗？

Question

我在很多项目中使用Hibernate。从那时起，我已经开发了我的项目，包括一个翻译表，其中包含每种语言的文本值，用于其他需要它的表

翻译表的映射文件

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
  <class dynamic-insert="false" dynamic-update="false" mutable="true" name="com.spectotechnologies.website.common.helper.TranslationValue" optimistic-lock="version" polymorphism="implicit" select-before-update="false" table="common_translations">
    <id name="keyTranslation">
      <generator class="native"/>
    </id>
    <property name="keyLanguage"/>
    <property name="tableName"/>
    <property name="fieldName"/>
    <property name="keyRow"/>
    <property name="value"/>
  </class>
</hibernate-mapping>

需要翻译的一个对象的示例：

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
  <class dynamic-insert="false" dynamic-update="false" mutable="true" name="com.spectotechnologies.website.common.helper.Category" optimistic-lock="version" polymorphism="implicit" select-before-update="false" table="common_categories">
    <id name="keyCategory">
      <generator class="native"/>
    </id>
    <property name="keyParent"/>
    <property name="tag"/>
    <property name="name" insert="false" update="false"/>
    <property name="description" insert="false" update="false"/>
  </class>
</hibernate-mapping>

目前，我使用这种SQL查询来加载对象

"SELECT" +
    " c.keyCategory," +
    " c.keyParent," +
    " c.tag," +
    " tn.value AS name," +
    " td.value AS description" +
" FROM common_categories c" +
// name
" LEFT JOIN common_translations tn" +
    " ON tn.tableName = 'common_categories'" +
    " AND tn.fieldName = 'name'" +
    " AND tn.keyRow = c.keyCategory" +
    " AND tn.keyLanguage = ?" +
// description
" LEFT JOIN common_translations td" +
    " ON td.tableName = 'common_categories'" +
    " AND td.fieldName = 'description'" +
    " AND td.keyRow = c.keyCategory" +
    " AND td.keyLanguage = ?" +
" ORDER BY" +
    " c.keyCategory ASC"

我想知道是否有可能在映射内部传输这种左连接，因为我需要包括参数：tableName、fieldName、language

非常感谢您的帮助，我将能够简化许多查询

编辑：

下面是一个我期望的例子：

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
  <class dynamic-insert="false" dynamic-update="false" mutable="true" name="com.spectotechnologies.website.common.helper.Category" optimistic-lock="version" polymorphism="implicit" select-before-update="false" table="common_categories">
    <id name="keyCategory">
      <generator class="native"/>
    </id>
    <property name="keyParent"/>
    <property name="tag"/>
    <one-to-many class="com.spectotechnologies.website.common.helper.TranslationValue"
  formula="tableName = 'common_categories' AND fieldName = 'name' AND keyLanguage = @language AND keyRow = keyCategory" name="name" />
    <one-to-many class="com.spectotechnologies.website.common.helper.TranslationValue"
  formula="tableName = 'common_categories' AND fieldName = 'description' AND keyLanguage = @language AND keyRow = keyCategory" name="description" />
  </class>
</hibernate-mapping>

在这种情况下，我需要创建一个可以在查询时注入的变量@language。这种解决方案有两个问题：

1. 我不知道是否可以将变量发布到映射范围

2. 公式目前不存在：https://hibernate.onjira.com/browse/HHH-944

Answer 1

对我来说，你只需要定义这两个实体之间的一对多和多对一关系。例如，每个类别都应该有翻译列表（或翻译集）

Answer 2

由于使用“自定义键”（tableName和fieldName）处理表很复杂，所以我将键反转。现在，需要多语言文本的对象具有所需文本的外键。对于所有多语言数据，它只需要两个表：

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;

多语言文本现在是这样的：

@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;
    }
}

每个需要使用多种语言的字段只需声明如下：

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

注意：

唯一的缺点是，每个多语言字段都会生成一个N+1选择，一旦找到解决方案，我就会更新我的答案