Question

我正在使用intellij和new来进行休眠。在为分支表生成类并执行时，我得到一个异常：

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个表共享相同的id序列） institute_id是制定表格的外键 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）：

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
当我使用每个实体的xml生成实体时，它为分支创建了以下xml，现在它可以正常工作。那怎么样？..

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。我不确切地知道消息的含义，但确切的是实体未正确映射：institute_id被映射两次：一次为Column，一次为JoinColumn 。 streetId也是如此。它还添加了不需要的属性。这是课程的样子：

@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。

在自动生成类时无法找到预期的辅助表

1 个答案: