Question

我有两个模型，Item和ShopSection。他们有多对多的关系。

@Entity(name = "item")
public class Item extends Model
{
    @ManyToMany(cascade = CascadeType.PERSIST)
    public Set<ShopSection> sections;
}

@Entity(name = "shop_section")
public class ShopSection extends Model
{
    public List<Item> findActiveItems(int page, int length)
    {
        return Item.find("select distinct i from Item i join i.sections as s where s.id = ?", id).fetch(page, length);
    }
}

findActiveItems用于查找某个部分中的项目，但我收到此错误：

org.hibernate.hql.ast.QuerySyntaxException: Item is not mapped [select distinct i from Item i join i.sections as s where s.id = ?]
        at org.hibernate.hql.ast.util.SessionFactoryHelper.requireClassPersister(SessionFactoryHelper.java:180)
        at org.hibernate.hql.ast.tree.FromElementFactory.addFromElement(FromElementFactory.java:111)
        at org.hibernate.hql.ast.tree.FromClause.addFromElement(FromClause.java:93)
        at org.hibernate.hql.ast.HqlSqlWalker.createFromElement(HqlSqlWalker.java:322)
        at org.hibernate.hql.antlr.HqlSqlBaseWalker.fromElement(HqlSqlBaseWalker.java:3441)
        at org.hibernate.hql.antlr.HqlSqlBaseWalker.fromElementList(HqlSqlBaseWalker.java:3325)
        at org.hibernate.hql.antlr.HqlSqlBaseWalker.fromClause(HqlSqlBaseWalker.java:733)
        at org.hibernate.hql.antlr.HqlSqlBaseWalker.query(HqlSqlBaseWalker.java:584)
        at org.hibernate.hql.antlr.HqlSqlBaseWalker.selectStatement(HqlSqlBaseWalker.java:301)
        at org.hibernate.hql.antlr.HqlSqlBaseWalker.statement(HqlSqlBaseWalker.java:244)
        at org.hibernate.hql.ast.QueryTranslatorImpl.analyze(QueryTranslatorImpl.java:254)
        at org.hibernate.hql.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:185)
        at org.hibernate.hql.ast.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:136)
        at org.hibernate.engine.query.HQLQueryPlan.<init>(HQLQueryPlan.java:101)
        at org.hibernate.engine.query.HQLQueryPlan.<init>(HQLQueryPlan.java:80)
        at org.hibernate.engine.query.QueryPlanCache.getHQLQueryPlan(QueryPlanCache.java:124)
        at org.hibernate.impl.AbstractSessionImpl.getHQLQueryPlan(AbstractSessionImpl.java:156)
        at org.hibernate.impl.AbstractSessionImpl.createQuery(AbstractSessionImpl.java:135)
        at org.hibernate.impl.SessionImpl.createQuery(SessionImpl.java:1770)
        at org.hibernate.ejb.AbstractEntityManagerImpl.createQuery(AbstractEntityManagerImpl.java:272)
        ... 8 more

我做错了什么？

Answer 1

您需要添加@Table这样的注释：

@Entity
@Table(name = "item")
public class Item extends Model
{
    @ManyToMany(cascade = CascadeType.PERSIST)
    public Set<ShopSection> sections;
}

@Entity
@Table(name = "shop_section")
public class ShopSection extends Model
{
    public List<Item> findActiveItems(int page, int length)
    {
        return Item.find("select distinct i from Item i join i.sections as s where s.id = ?", id).fetch(page, length);
    }
}

Answer 2

您需要从“项目”中选择，而不是从“项目”中选择。实体名称区分大小写。

Answer 3

您需要在hibernate.cfg.xml中声明Object

org.hibernate.hql.ast.QuerySyntaxException：未映射TABLE NAME

3 个答案: