自动生成类时找不到预期的辅助表

Question

我正在使用 intellij 和新的休眠模式。在为分支表生成类并执行时出现异常：

• 分支表包含以下列：id, institute_id, street_id, name。
  id 是超级表的外键（我有 2 个共享相同 id 序列的表）。
  institute_id 是外键机构表的键。
  street_id 是街道表的外键。

• intellij创建的Branch类是：

  @Entity
  public class Branch {
   private long id;
  
   @javax.persistence.Column(name = "id", nullable = false, insertable = true, updatable = true, length = 19, precision = 0)
   @Id
   public long getId() {
      return id;
   }
  
   public void setId(long id) {
      this.id = id;
   }
  
   private long instituteId;
  
   @javax.persistence.Column(name = "institute_id", nullable = false, insertable = true, updatable = true, length = 19, precision = 0)
   @Basic
   public long getInstituteId() {
      return instituteId;
   }
  
   public void setInstituteId(long instituteId) {
      this.instituteId = instituteId;
   }
  
   private long streetId;
  
   @javax.persistence.Column(name = "street_id", nullable = true, insertable = true, updatable = true, length = 19, precision = 0)
   @Basic
   public long getStreetId() {
      return streetId;
   }
  
   public void setStreetId(long streetId) {
      this.streetId = streetId;
   }
  
   private String name;
  
   @javax.persistence.Column(name = "name", nullable = false, insertable = true, updatable = true, length = 50, precision = 0)
   @Basic
   public String getName() {
      return name;
   }
  
   public void setName(String name) {
      this.name = name;
   }
  
   @Override
   public boolean equals(Object o) {
      if (this == o) return true;
      if (o == null || getClass() != o.getClass()) return false;
  
      Branch branch = (Branch) o;
  
      if (id != branch.id) return false;
      if (instituteId != branch.instituteId) return false;
      if (streetId != branch.streetId) return false;
      if (name != null ? !name.equals(branch.name) : branch.name != null) return false;
  
      return true;
   }
  
   @Override
   public int hashCode() {
      int result = (int) (id ^ (id >>> 32));
      result = 31 * result + (int) (instituteId ^ (instituteId >>> 32));
      result = 31 * result + (int) (streetId ^ (streetId >>> 32));
      result = 31 * result + (name != null ? name.hashCode() : 0);
      return result;
   }
  
   private Institute instituteByInstituteId;
  
   @ManyToOne
   public
   @javax.persistence.JoinColumn(name = "institute_id", referencedColumnName = "id", nullable = false, table = "branch")
   Institute getInstituteByInstituteId() {
      return instituteByInstituteId;
   }
  
   public void setInstituteByInstituteId(Institute instituteByInstituteId) {
      this.instituteByInstituteId = instituteByInstituteId;
   }
  
   private Street streetByStreetId;
  
   @ManyToOne
   public
   @javax.persistence.JoinColumn(name = "street_id", referencedColumnName = "id", table = "branch")
   Street getStreetByStreetId() {
      return streetByStreetId;
   }
  
   public void setStreetByStreetId(Street streetByStreetId) {
      this.streetByStreetId = streetByStreetId;
   }
  }
  

• 这是我执行的代码（intellij 自动创建的）：

  public static void main(final String[] args) throws Exception {
      final Session session = getSession();
      try {
          System.out.println("querying all the managed entities...");
          final Map metadataMap = session.getSessionFactory().getAllClassMetadata();
          for (Object key : metadataMap.keySet()) {
              final ClassMetadata classMetadata = (ClassMetadata) metadataMap.get(key);
              final String entityName = classMetadata.getEntityName();
              final Query query = session.createQuery("from " + entityName);
              System.out.println("executing: " + query.getQueryString());
              for (Object o : query.list()) {
                  System.out.println("  " + o);
              }
          }
      } finally {
          session.close();
      }
  }
  

• 我遇到了以下异常：

  org.hibernate.AnnotationException: Cannot find the expected secondary table: no branch available for GreenWheels.Data.Entities.Branch
  

更新
当我为每个实体生成带有 xml 的实体时，它为分支创建了以下 xml，现在它可以工作了。怎么样？..

Branch.nbm.xml
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
  "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
  "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>

    <class name="GreenWheels.Data.Entities.Branch" table="branch" catalog="greenwheels">
        <id name="id">
            <column name="id" sql-type="bigint" length="19" not-null="true"/>
        </id>
        <property name="instituteId">
            <column name="institute_id" sql-type="bigint" length="19" not-null="true"/>
        </property>
        <property name="streetId">
            <column name="street_id" sql-type="bigint" length="19"/>
        </property>
        <property name="name">
            <column name="name" sql-type="varchar" length="50" not-null="true"/>
        </property>
        <many-to-one name="instituteByInstituteId" class="GreenWheels.Data.Entities.Institute">
            <column name="institute_id" not-null="true"/>
        </many-to-one>
        <many-to-one name="streetByStreetId" class="GreenWheels.Data.Entities.Street">
            <column name="street_id"/>
        </many-to-one>
    </class>
</hibernate-mapping>

Answer 1

生成的类不正确。我不知道该消息的确切含义，但可以肯定的是该实体未正确映射：institute_id 被映射两次：一次为Column，一次为JoinColumn。 streetId 也一样。它还添加了不需要的属性。下面是这个类的样子：

@Entity
public class Branch {
 private long id;

 @Column(name = "id", nullable = false, length = 19, precision = 0)
 @Id
 public long getId() {
    return id;
 }

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

 private String name;

 @Column(name = "name", nullable = false, length = 50)
 public String getName() {
    return name;
 }

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

 private Institute institute;

 @ManyToOne
 @JoinColumn(name = "institute_id", nullable = false)
 public Institute getInstitute() {
    return institute;
 }

 public void setInstitute(Institute institute) {
    this.institute = institute;
 }

 private Street street;

 @ManyToOne
 @JoinColumn(name = "street_id")
 public Street getStreet() {
    return street;
 }

 public void setStreet(Street street) {
    this.street = street;
 }
}

我的猜测是错误是由 JoinColumn 注释的table = "branch" 属性调用的。