Question

我正在尝试创建一个示例EAR，maven项目，我几乎所有工作都有效但由于某种原因，我的实体类存在问题。在我的数据库中，我有多对一的关系，尝试使用我的Entity类中的另一个表加入列是一件痛苦的事。我已经搜索了一段时间，但我没有想出任何东西。我很感激在这方面提供一些帮助。

import java.io.Serializable;
import javax.persistence.*;


/**
 * The persistent class for the "city" database table.
 * 
 */
@Entity
@Table(name="\"city\"")
@NamedQuery(name="City.findAll", query="SELECT c FROM City c")
public class City extends com.dozie.example.util.Entity implements Serializable {
    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    @Column(name="\"id\"")
    private Integer id;

    @Column(name="\"country_id\"")
    private int countryId;

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

    //bi-directional many-to-one association to Country
    @ManyToOne
    @JoinColumns({
        @JoinColumn(name="\"country_id\"", referencedColumnName="\"id\"")
        })
    private Country country;

    public City() {
    }

    public Integer getId() {
        return this.id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public int getCountryId() {
        return this.countryId;
    }

    public void setCountryId(int countryId) {
        this.countryId = countryId;
    }

    public String getName() {
        return this.name;
    }

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

    public Country getCountry() {
        return this.country;
    }

    public void setCountry(Country country) {
        this.country = country;
    }

}

和我的其他实体类

import java.io.Serializable;
import javax.persistence.*;
import java.util.Set;


/**
 * The persistent class for the "country" database table.
 * 
 */
@Entity
@Table(name="\"country\"")
@NamedQuery(name="Country.findAll", query="SELECT c FROM Country c")
public class Country extends com.dozie.example.util.Entity implements Serializable {
    private static final long serialVersionUID = 1L;
    private Integer id;
    private String name;
    private Set<City> cities;

    public Country() {
    }


    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    @Column(name="\"id\"")
    public Integer getId() {
        return this.id;
    }

    public void setId(Integer id) {
        this.id = id;
    }


    @Column(name="\"name\"")
    public String getName() {
        return this.name;
    }

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


    //bi-directional many-to-one association to City
    @OneToMany(mappedBy="country")
    public Set<City> getCities() {
        return this.cities;
    }

    public void setCities(Set<City> cities) {
        this.cities = cities;
    }

    public City addCity(City city) {
        getCities().add(city);
        city.setCountry(this);

        return city;
    }

    public City removeCity(City city) {
        getCities().remove(city);
        city.setCountry(null);

        return city;
    }

}

这里是我的数据库表的脚本，这是一个Postgres数据库

CREATE TABLE city
(
  id integer NOT NULL,
  country_id integer NOT NULL,
  name character varying(30) NOT NULL,
  CONSTRAINT city_pk PRIMARY KEY (id),
  CONSTRAINT city_country_fk FOREIGN KEY (country_id)
      REFERENCES country (id) MATCH SIMPLE
      ON UPDATE NO ACTION ON DELETE CASCADE,
  CONSTRAINT city_name_idx UNIQUE (name)
)

CREATE TABLE country
(
  id integer NOT NULL,
  name character varying(10) NOT NULL,
  CONSTRAINT country_pk PRIMARY KEY (id),
  CONSTRAINT country_name_idx UNIQUE (name)
)

当我的服务器运行时，我收到此错误消息

javax.persistence.PersistenceException：[PersistenceUnit： cookbook-entities]无法构建EntityManagerFactory org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory（Ejb3Configuration.java:915）在 org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory（Ejb3Configuration.java:890）在 org.hibernate.ejb.HibernatePersistence.createContainerEntityManagerFactory（HibernatePersistence.java:74）在 org.glassfish.persistence.jpa.PersistenceUnitLoader.loadPU（PersistenceUnitLoader.java:206）在 org.glassfish.persistence.jpa.PersistenceUnitLoader。（PersistenceUnitLoader.java:120）在 org.glassfish.persistence.jpa.JPADeployer $ 1.visitPUD（JPADeployer.java:224）在 org.glassfish.persistence.jpa.JPADeployer $ PersistenceUnitDescriptorIterator.iteratePUDs（JPADeployer.java:495）在 org.glassfish.persistence.jpa.JPADeployer.createEMFs（JPADeployer.java:233）在 org.glassfish.persistence.jpa.JPADeployer.prepare（JPADeployer.java:168）在 com.sun.enterprise.v3.server.ApplicationLifecycle.prepareModule（ApplicationLifecycle.java:871）在 com.sun.enterprise.v3.server.ApplicationLifecycle.deploy（ApplicationLifecycle.java:410）在 com.sun.enterprise.v3.server.ApplicationLifecycle.deploy（ApplicationLifecycle.java:240）在 org.glassfish.deployment.admin.DeployCommand.execute（DeployCommand.java:389）在 com.sun.enterprise.v3.admin.CommandRunnerImpl $ 1.execute（CommandRunnerImpl.java:348）在 com.sun.enterprise.v3.admin.CommandRunnerImpl.doCommand（CommandRunnerImpl.java:363）在 com.sun.enterprise.v3.admin.CommandRunnerImpl.doCommand（CommandRunnerImpl.java:1085）在 com.sun.enterprise.v3.admin.CommandRunnerImpl.access $ 1200（CommandRunnerImpl.java:95）在 com.sun.enterprise.v3.admin.CommandRunnerImpl $ ExecutionContext.execute（CommandRunnerImpl.java:1291）在 com.sun.enterprise.v3.admin.CommandRunnerImpl $ ExecutionContext.execute（CommandRunnerImpl.java:1259）在 com.sun.enterprise.v3.admin.AdminAdapter.doCommand（AdminAdapter.java:461）在 com.sun.enterprise.v3.admin.AdminAdapter.service（AdminAdapter.java:212）在 com.sun.grizzly.tcp.http11.GrizzlyAdapter.service（GrizzlyAdapter.java:179）在 com.sun.enterprise.v3.server.HK2Dispatcher.dispath（HK2Dispatcher.java:117）在 com.sun.enterprise.v3.services.impl.ContainerMapper $ Hk2DispatcherCallable.call（ContainerMapper.java:354）在 com.sun.enterprise.v3.services.impl.ContainerMapper.service（ContainerMapper.java:195）在 com.sun.grizzly.http.ProcessorTask.invokeAdapter（ProcessorTask.java:849）在 com.sun.grizzly.http.ProcessorTask.doProcess（ProcessorTask.java:746）在 com.sun.grizzly.http.ProcessorTask.process（ProcessorTask.java:1045）在 com.sun.grizzly.http.DefaultProtocolFilter.execute（DefaultProtocolFilter.java:228）在 com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter（DefaultProtocolChain.java:137）在 com.sun.grizzly.DefaultProtocolChain.execute（DefaultProtocolChain.java:104）在 com.sun.grizzly.DefaultProtocolChain.execute（DefaultProtocolChain.java:90）在 com.sun.grizzly.http.HttpProtocolChain.execute（HttpProtocolChain.java:79）在 com.sun.grizzly.ProtocolChainContextTask.doCall（ProtocolChainContextTask.java:54）在 com.sun.grizzly.SelectionKeyContextTask.call（SelectionKeyContextTask.java:59）在com.sun.grizzly.ContextTask.run（ContextTask.java:71）at com.sun.grizzly.util.AbstractThreadPool $ Worker.doWork（AbstractThreadPool.java:532）在 com.sun.grizzly.util.AbstractThreadPool $ Worker.run（AbstractThreadPool.java:513）在java.lang.Thread.run（Thread.java:722）引起： org.hibernate.MappingException：无法找到具有逻辑的列姓名：＆＃34; id＆＃34;在org.hibernate.mapping.Table（country）及其相关内容中在supertables和次要表 org.hibernate.cfg.Ejb3JoinColumn.checkReferencedColumnsType（Ejb3JoinColumn.java:552）在 org.hibernate.cfg.BinderHelper.createSyntheticPropertyReference（BinderHelper.java:257）在 org.hibernate.cfg.ToOneFkSecondPass.doSecondPass（ToOneFkSecondPass.java:116）在 org.hibernate.cfg.Configuration.processEndOfQueue（Configuration.java:1521）在 org.hibernate.cfg.Configuration.processFkSecondPassInOrder（Configuration.java:1446）在 org.hibernate.cfg.Configuration.secondPassCompile（Configuration.java:1351）在 org.hibernate.cfg.Configuration.buildSessionFactory（Configuration.java:1733）在 org.hibernate.ejb.EntityManagerFactoryImpl。（EntityManagerFactoryImpl.java:94）在 org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory（Ejb3Configuration.java:905） ......还有38个

当我尝试更新City实体中的连接列而不包含referenceColumnName时，我得到一个不同的错误，说物理名称与逻辑名称不同。另外我注意到在实体课程中我不能用引号命名我的字段（我不知道这是否是正常行为）我认为这可能与我的问题有关但是我试图在没有引号的情况下这样做，并且每当发生这种情况时我都会犯错误。

我很感激你的帮助。

Answer 1

你到处都在添加双引号。你不应该。例如，

 @Table(name="\"city\"")

应该是

@Table(name="city")

和

@Column(name="\"id\"")

应该是

@Column(name="id")

和

@JoinColumns({
    @JoinColumn(name="\"country_id\"", referencedColumnName="\"id\"")
    })

应该只是

@JoinColumn(name="country_id")

无法访问实体类中的字段

1 个答案: