在自動生成類時找不到預期的輔助表

Question

我正在使用intellij，並且是用於休眠的新類。同時爲分支表類和執行我得到一個異常：

• 分支表包含以下幾列：id, institute_id, street_id, name。
  id是超級表的外鍵（我有2個表共享相同的id序列）。
  institute_id是實現表的外鍵。
  street_id是街道表的外鍵。

• 通過的IntelliJ建立的分支類是：

  @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; 
  } 
  } 
  

• 這是我執行代碼（的IntelliJ創造了這個自動）：

  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(); 
      } 
  } 
  

• 我有以下異常：

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

UPDATE
當我爲每個實體生成xml實體時，它爲分支創建了以下xml，現在它工作。那是怎麼回事？

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

生成的類是不正確的。我不確切知道消息的含義，但可以肯定的是，實體未正確映射：institute_id被映射兩次：一次爲Column，一次爲JoinColumn。相同的爲streetId。它還增加了不需要的屬性。這裏的類應該怎麼樣子：

@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; 
} 
} 

我的猜測是錯誤由JoinColumn註解的table = "branch"屬性調用。