org.hibernate.exception.sqlgrammareexception:无法初始化集合

我有三个表tbl_category、tbl_Advertisiment和tbl_linkcategoryadvert（有多对多关联b/w category&Advertisiment）

我的POJO如下所示

Advertisment.java

@Entity
@Table(name="tbl_advertisment")
public class Advertisment implements Serializable {
    private long id;
    private String title;
    private String message;
    private Set<Category> categories;

    public Advertisment(String title, String message) {
        this.title = title;
        this.message = message;
        this.categories=new HashSet<Category>();
    }

    protected Advertisment() {
    }

    @Id
    @GeneratedValue
    protected long getId() {
        return id;
    }

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

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    @Column(nullable=false)
    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    @ManyToMany(mappedBy="adverts")
    public Set<Category> getCategories() {
        return categories;
    }

    public void setCategories(Set<Category> categories) {
        this.categories = categories;
    }
}

@Entity
@Table(name="tbl_category")
public class Category implements Serializable {
    private long id;
    private String title;
    private Set<Advertisment> adverts=new HashSet<Advertisment>();

    public Category(String title) {
        this.title = title;
    }

    protected Category() {
    }

    @ManyToMany
    @JoinTable(name="tbl_linkcategoryadvert")
    public Set<Advertisment> getAdverts() {
        return adverts;
    }

    public void setAdverts(Set<Advertisment> adverts) {
        this.adverts = adverts;
    }

    public void addAdvert(Advertisment advert){
        adverts.add(advert);
    }

    @Id
    @GeneratedValue
    protected long getId() {
        return id;
    }

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

    @Column(unique=true,nullable=false)
    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }
}

DAO.java

@Entity
@Table(name="tbl_advertisment")
public class Advertisment implements Serializable {
    private long id;
    private String title;
    private String message;
    private Set<Category> categories;

    public Advertisment(String title, String message) {
        this.title = title;
        this.message = message;
        this.categories=new HashSet<Category>();
    }

    protected Advertisment() {
    }

    @Id
    @GeneratedValue
    protected long getId() {
        return id;
    }

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

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    @Column(nullable=false)
    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    @ManyToMany(mappedBy="adverts")
    public Set<Category> getCategories() {
        return categories;
    }

    public void setCategories(Set<Category> categories) {
        this.categories = categories;
    }
}

@Entity
@Table(name="tbl_category")
public class Category implements Serializable {
    private long id;
    private String title;
    private Set<Advertisment> adverts=new HashSet<Advertisment>();

    public Category(String title) {
        this.title = title;
    }

    protected Category() {
    }

    @ManyToMany
    @JoinTable(name="tbl_linkcategoryadvert")
    public Set<Advertisment> getAdverts() {
        return adverts;
    }

    public void setAdverts(Set<Advertisment> adverts) {
        this.adverts = adverts;
    }

    public void addAdvert(Advertisment advert){
        adverts.add(advert);
    }

    @Id
    @GeneratedValue
    protected long getId() {
        return id;
    }

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

    @Column(unique=true,nullable=false)
    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }
}

我不提供DAO.java，因为它只包含Hibernate样板代码

当我运行main类时，会出现以下异常：

SEVERE: Unknown column 'adverts0_.categories_id' in 'field list'
org.hibernate.exception.SQLGrammarException: could not initialize a collection: [hibernate.Category.adverts#3]
    at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:67)
    at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43)
    at org.hibernate.loader.Loader.loadCollection(Loader.java:2001)
    at org.hibernate.loader.collection.CollectionLoader.initialize(CollectionLoader.java:36)
    at org.hibernate.persister.collection.AbstractCollectionPersister.initialize(AbstractCollectionPersister.java:565)
    at org.hibernate.event.def.DefaultInitializeCollectionEventListener.onInitializeCollection(DefaultInitializeCollectionEventListener.java:60)
    at org.hibernate.impl.SessionImpl.initializeCollection(SessionImpl.java:1716)
    at org.hibernate.collection.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:344)
    at org.hibernate.collection.PersistentSet.add(PersistentSet.java:189)
    at hibernate.Category.addAdvert(Category.java:48)
    at hibernate.client.PostAdvertisment.post(PostAdvertisment.java:35)
    at hibernate.client.PostAdvertisment.main(PostAdvertisment.java:56)
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column 'adverts0_.categories_id' in 'field list'
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:409)
    at com.mysql.jdbc.Util.getInstance(Util.java:384)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1054)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3566)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3498)
    at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1959)
    at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2113)
    at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2568)
    at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2113)

请帮帮我

---

我的表格如下所示：

1。tbl_广告

id PK BIGINT
title VARCHAR(255)

advert_id FK references(advert.id)
category_id FK references(category.id)

2。tbl_类别

id PK BIGINT
title VARCHAR(255)

3。tbl_linkcategoryadvert

id PK BIGINT
title VARCHAR(255)

advert_id FK references(advert.id)
category_id FK references(category.id)

现在我的问题是

表“link\u categoryadvert”中的字段名称是否有误

hibernate如何查找列名和映射

@JoinTable注释的其他可能属性是什么

---

您希望在拥有关系的类上使用@Jointable注释。您需要在广告类上放置@Jointable注释。

Hibernate正在为您的join列生成列名“categories\u id”，其中您的表使用名称“category\u id”。参考指南中有一个示例。在周围的文本中也有一些相关的细节。您只需将Category.getAdverts（）上的映射设置为：

@JoinTable(
    name="tbl_linkcategoryadvert",
    joinColumns=@JoinColumn(name="category_id"),
    inverseJoinColumns=@JoinColumn(name="advert_id")
)

---

联接表tbl_linkcategoryadvert中的外键是否具有名称Category_id和Advertisiments_id？否则，您可能必须配置@JoinTable映射以反映这些名称。您能告诉我

广告

表是什么样子吗？也许您需要定义多对多列，例如

@JoinTable（name=“adverts”，joinColumns=@JoinColumn（name=“cat\u id”）

？请以后编辑您的问题以提供更多详细信息。此外，请查看编辑器中的格式帮助链接。