Hibernate多列多对一连接映射
我正在尝试使用Hibernate将一个表作为一组DTO映射到另一个DTO。我遇到了麻烦,因为我需要使用两列进行映射。请告诉我在hibernate映射文件中写什么来进行映射,因为无论我在映射的“连接”部分中放了什么,它都不被接受为有效格式 我试图用hibernate映射的DTO: 公共类CoverageDTO扩展BaseDTO{Hibernate多列多对一连接映射,hibernate,join,mapping,many-to-one,Hibernate,Join,Mapping,Many To One,我正在尝试使用Hibernate将一个表作为一组DTO映射到另一个DTO。我遇到了麻烦,因为我需要使用两列进行映射。请告诉我在hibernate映射文件中写什么来进行映射,因为无论我在映射的“连接”部分中放了什么,它都不被接受为有效格式 我试图用hibernate映射的DTO: 公共类CoverageDTO扩展BaseDTO{ private SupplierDTO supplierDTO; private MarketDTO marketDTO; private Float price;
private SupplierDTO supplierDTO;
private MarketDTO marketDTO;
private Float price;
private String currency;
private Set<SpecialRuleDTO> specialRules = new HashSet<SpecialRuleDTO>(0);
供应商特殊规则表-列出可应用于供应商的特殊规则
CREATE TABLE supplier_special_rules (
SUPPLIER_SPECIAL_RULE_ID bigint(20) unsigned NOT NULL auto_increment,
SUPPLIER_ID bigint(20) unsigned NOT NULL,
NAME varchar(128) NOT NULL,
TYPE varchar(128) NOT NULL,
VALUE float NOT NULL,
PRIMARY KEY (SUPPLIER_SPECIAL_RULE_ID)
) DEFAULT;
供应商覆盖范围特殊规则-列出应适用于供应商和市场的特殊规则
CREATE TABLE supplier_coverage_special_rules (
SUPPLIER_COVERAGE_SPECIAL_RULE_ID bigint(20) unsigned NOT NULL auto_increment,
MARKET_ID bigint(20) unsigned NOT NULL,
SUPPLIER_SPECIAL_RULE_ID bigint(20) unsigned NOT NULL,
PRIMARY KEY (SUPPLIER_COVERAGE_SPECIAL_RULE_ID)
) DEFAULT;
因此,从SQL级别考虑,我需要使用supplier_coverage_special_rules表中的信息,即通过匹配MARKET_ID和supplier_ID列,将supplier_special_规则映射到coverage表中。我认为下面的映射可以做到这一点,但它似乎不是有效的映射语法
<hibernate-mapping package="net.dtopath">
<class name="CoverageDTO" table="coverage">
<id column="COVERAGE_ID" name="ID">
<generator class="native"/>
</id>
<many-to-one class="net.dtopath.SupplierDTO" column="SUPPLIER_ID" name="supplierDTO"/>
<many-to-one class="net.dtopath.MarketDTO" column="MARKET_ID" name="marketDTO"/>
<property name="price" type="float">
<column name="PRICE" not-null="false"/>
</property>
<property name="currency" type="string">
<column name="CURRENCY" not-null="false"/>
</property>
<!-- Start of the bit that needs editing as it's wrong -->
<join table="SUPPLIER_COVERAGE_SPECIAL_RULES">
<key>
<column name="SUPPLIER_ID" not-null="true" />
<column name="MARKET_ID" not-null="true" />
</key>
<many-to-one name="specialRules" column="SUPPLIER_SPECIAL_RULE_ID" class="SupplierSpecialRuleDTO" not-null="true" />
</join>
<!-- End of the bit that needs editing as it's wrong -->
</class>
</hibernate-mapping>
关于如何进行这种映射有什么想法吗
(是的,我需要映射供应商ID和市场ID,而不是各种其他要求的覆盖范围ID)
编辑
我在别处发现一个建议,建议我应该使用属性来定义应该在其上进行连接的键,例如:
<properties name="keysCoverageSpecialRules">
<property name="supplierID" column="SUPPLIER_ID" insert="false" update="false"/>
<property name="marketID" column="MARKET_ID" insert="false" update="false"/>
</properties>
<set name="specialRules" table="SUPPLIER_COVERAGE_SPECIAL_RULES">
<key property-ref="keysCoverageSpecialRules">
</key>
<many-to-many class="SupplierSpecialRuleDTO" unique="true" column="SUPPLIER_SPECIAL_RULE_ID"/>
</set>
但这会给出一个错误“org.hibernate.MappingException:collection外键映射的列数错误:net.dtopath.CoverageDTO.specialRules类型:component[supplierID,networkID]”我找到了答案,其实很简单:
<set name="specialRules" table="SUPPLIER_COVERAGE_SPECIAL_RULES" >
<key column="MARKET_ID" />
<many-to-many class="SupplierSpecialRuleDTO" unique="true" column="SUPPLIER_SPECIAL_RULE_ID" />
</set>
连接的每个步骤只需要一列连接。我试图一次告诉hibernate关于两列的内容,这是错误的
我也错过了,因为Hibernate知道类SupplierSpecialRuleDTO,它知道对象来自哪个表
<set name="specialRules" table="SUPPLIER_COVERAGE_SPECIAL_RULES" >
<key column="MARKET_ID" />
<many-to-many class="SupplierSpecialRuleDTO" unique="true" column="SUPPLIER_SPECIAL_RULE_ID" />
</set>