java：休眠一對多關聯

Question

我曾經遇到過一些hibernate框架的問題。

假設我有一個人，一個人有多個地址。下面是我的代碼，

/* Person entity*/ 
@Entity 
@Table(name="person") 
public class Person implements Serializable{ 

    private static final long serialVersionUID = 7635130386543844954L; 

    @Id 
    @Column(name="person_id") 
    private Integer personId; 

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

    @Column(name="ic_no") 
    private String icNo; 

    @OneToMany(fetch=FetchType.EAGER) 
    @JoinTable(name="address", 
joinColumns{@JoinColumn(name="name")},inverseJoinColumns={@JoinColumn(name="address_id")}) 
    List<Address> listAddress = new ArrayList<Address>(); 

    public Integer getPersonId() { 
     return personId; 
    } 

    public void setPersonId(Integer personId) { 
     this.personId = personId; 
    } 

    public String getName() { 
     return name; 
    } 

    public void setName(String name) { 
     this.name = name; 
    } 

    public String getIcNo() { 
     return icNo; 
    } 

    public void setIcNo(String icNo) { 
     this.icNo = icNo; 
    } 

} 

/* Address entity*/ 
@Entity 
@Table(name="address") 
public class Address implements Serializable{ 

    private static final long serialVersionUID = 1371825219482824135L; 

    @Id 
    @Column(name="address_id") 
    private Integer addressId; 

    @Column(name="address") 
    private String address; 

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

    public Integer getAddressId() { 
     return addressId; 
    } 

    public void setAddressId(Integer addressId) { 
     this.addressId = addressId; 
    } 

    public String getAddress() { 
     return address; 
    } 

    public void setAddress(String address) { 
     this.address = address; 
    } 

    public String getName() { 
     return name; 
    } 

    public void setName(String name) { 
     this.name = name; 
    } 
} 


/* DAO code*/ 
List<ProductDetails>list = hibernateTemplate.find("from Person where Name=?",new Object[]{name}); 

當我嘗試執行程序時，我得到的異常如下：

Exception in thread "main" org.springframework.dao.InvalidDataAccessResourceUsageException: could not initialize a collection: [com.inventory.inventory.vo.Person.listAddress#1]; nested exception is org.hibernate.exception.SQLGrammarException: could not initialize a collection: [com.inventory.inventory.vo.Person.listAddress#1] 
    at org.springframework.orm.hibernate3.SessionFactoryUtils.convertHibernateAccessException(SessionFactoryUtils.java:630) 
    at org.springframework.orm.hibernate3.HibernateAccessor.convertHibernateAccessException(HibernateAccessor.java:412) 
    at org.springframework.orm.hibernate3.HibernateTemplate.doExecute(HibernateTemplate.java:424) 
    at org.springframework.orm.hibernate3.HibernateTemplate.executeWithNativeSession(HibernateTemplate.java:374) 
    at org.springframework.orm.hibernate3.HibernateTemplate.find(HibernateTemplate.java:921) 
    at com.inventory.inventory.dao.impl.ProductsDAOImpl.getProductsByCode(ProductsDAOImpl.java:28) 
    at Main.main(Main.java:14) 
Caused by: org.hibernate.exception.SQLGrammarException: could not initialize a collection: [com.inventory.inventory.vo.Person.listAddress#1] 
    at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:92) 
    at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66) 
    at org.hibernate.loader.Loader.loadCollection(Loader.java:2069) 
    at org.hibernate.loader.collection.CollectionLoader.initialize(CollectionLoader.java:62) 
    at org.hibernate.persister.collection.AbstractCollectionPersister.initialize(AbstractCollectionPersister.java:628) 
    at org.hibernate.event.def.DefaultInitializeCollectionEventListener.onInitializeCollection(DefaultInitializeCollectionEventListener.java:83) 
    at org.hibernate.impl.SessionImpl.initializeCollection(SessionImpl.java:1853) 
    at org.hibernate.collection.AbstractPersistentCollection.forceInitialization(AbstractPersistentCollection.java:476) 
    at org.hibernate.engine.StatefulPersistenceContext.initializeNonLazyCollections(StatefulPersistenceContext.java:899) 
    at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:275) 
    at org.hibernate.loader.Loader.doList(Loader.java:2294) 
    at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2172) 
    at org.hibernate.loader.Loader.list(Loader.java:2167) 
    at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:448) 
    at org.hibernate.hql.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:363) 
    at org.hibernate.engine.query.HQLQueryPlan.performList(HQLQueryPlan.java:196) 
    at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1258) 
    at org.hibernate.impl.QueryImpl.list(QueryImpl.java:102) 
    at org.springframework.orm.hibernate3.HibernateTemplate$30.doInHibernate(HibernateTemplate.java:930) 
    at org.springframework.orm.hibernate3.HibernateTemplate.doExecute(HibernateTemplate.java:419) 
    ... 4 more 

<b>Caused by: org.postgresql.util.PSQLException: ERROR: operator does not exist: character varying = integer</b> 

    Hint: No operator matches the given name and argument type(s). You might need to add explicit type casts. 
    Position: 305 
    at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2102) 
    at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1835) 
    at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:257) 
    at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:500) 
    at org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:388) 
    at org.postgresql.jdbc2.AbstractJdbc2Statement.executeQuery(AbstractJdbc2Statement.java:273) 
    at org.apache.commons.dbcp.DelegatingPreparedStatement.executeQuery(DelegatingPreparedStatement.java:96) 
    at org.apache.commons.dbcp.DelegatingPreparedStatement.executeQuery(DelegatingPreparedStatement.java:96) 
    at org.hibernate.jdbc.AbstractBatcher.getResultSet(AbstractBatcher.java:208) 
    at org.hibernate.loader.Loader.getResultSet(Loader.java:1849) 
    at org.hibernate.loader.Loader.doQuery(Loader.java:718) 
    at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:270) 
    at org.hibernate.loader.Loader.loadCollection(Loader.java:2062) 
    ... 21 more 

我讓它唯一不同的是，我使用列「名」與連接表和逆連接的字符數據類型是使用整數數據類型的地址標識。無論如何，映射視圖對象與不同的數據類型？

Answer 1

試試這個

修改Person類作爲

@OneToMany(cascade=mappedBy = "person", fetch = FetchType.EAGER) 
private List<Address> listAddress = new ArrayList<Address>(); 

修改地址類作爲

@JoinColumn(name = "person_id", referencedColumnName = "person_id") 
@ManyToOne 
private Person person;