Question

我发现，这是一个非常简单的查询，比如

        Session s = sessionFactory.getCurrentSession();
        List<Mod> list = s.createQuery("from Mod m where m.modNameShort=:modName")
                .setParameter("modName", modName)
                .setCacheable(true)
                .list();

缓存得很好。

但缓存不适用于一对多选择，如下所示：

List<ModVersion> list = s.createQuery("select m.modsVersionses from Mod m")
                .setCacheable(true)
                .list();

它仍会在第二次和下次呼叫时向DB发出请求。

我有

        props.setProperty("hibernate.cache.provider_class", "org.hibernate.cache.EhCacheProvider");
        props.setProperty("hibernate.cache.region.factory_class", "org.hibernate.cache.ehcache.EhCacheRegionFactory");
        props.setProperty("hibernate.cache.use_second_level_cache", "true");
        props.setProperty("hibernate.cache.use_query_cache", "true");
        factoryBean.setHibernateProperties(props);

，Mod对象看起来像

@Entity
@Table(name = "mods", catalog = "artfunpw")
@Cache(usage = CacheConcurrencyStrategy.TRANSACTIONAL)
public class Mod implements java.io.Serializable {
***
 @OneToMany(fetch = FetchType.LAZY, mappedBy = "mods") 
    @OrderBy("ReleaseDate desc")
    public Set<ModVersion> getModsVersionses() {
        return this.modsVersionses;
    }
***

ModVersion对象看起来像

@Entity
@Table(name = "mods_versions", catalog = "artfunpw", uniqueConstraints = @UniqueConstraint(columnNames = "VersionNumber"))
@Cache(usage = CacheConcurrencyStrategy.TRANSACTIONAL)
public class ModVersion implements java.io.Serializable {

如何为这种一对多查询启用缓存？

谢谢！

Answer 1

可能，我的问题是重复的。

我在Using hibernate 2nd level cache or query cache for lazy fetch queries和http://docs.jboss.org/hibernate/core/3.6/reference/en-US/html_single/#performance-cache-mapping

找到了答案

我应该添加@Cache(usage = CacheConcurrencyStrategy.READ_WRITE)：

    @OneToMany(fetch = FetchType.LAZY, mappedBy = "mods", cascade = {CascadeType.ALL})  
    @OrderBy("ReleaseDate desc")
    @Cache(usage = CacheConcurrencyStrategy.READ_WRITE) 
    public Set<ModVersion> getModsVersionses() {
        return this.modsVersionses;
    }

具有内部对象的查询不会在Hibernate

1 个答案: