Lazy loading of Blob properties of one class

Posted by Khosro on Stack Overflow See other posts from Stack Overflow or by Khosro
Published on 2010-03-19T15:53:28Z Indexed on 2010/03/19 16:21 UTC
Read the original article Hit count: 489

Filed under:
|
|

Hi, My class contains "summary" and "title" properties those are Blob and other properties. Code:(I write some part of class)


public class News extends BaseEntity{
   @Lob
    @Basic(fetch = FetchType.LAZY)
    public String getSummary() {
        return summary;
    }
@Lob
@Basic(fetch = FetchType.LAZY)
public String getTitle() {
        return title;
       }

@Temporal(TemporalType.TIMESTAMP)
public Date getPublishDate() {
    return publishDate;
}

}

I instrument this class to lazy load of Blob properties using this class "org.hibernate.tool.instrument.javassist.InstrumentTask".
When i write this code to retrieve only summary of new ,

newsDAO.findByid(1L).getSummary();
Hibernate generates these queries:

Hibernate:
    select
        news0_.id as id1_,
        news0_.entityVersion as entityVe2_1_,
        news0_.publishDate as publish15_1_,
        news0_.url as url1_
    from
        News news0_
Hibernate:
    select
        news_.summary as summary1_,
        news_.title as title1_
    from
        News news_
    where
        news_.id=?

I have two qurestions:
1.I only want to retrieve "summary" property not "title" property,but Hibernate queries show that it also retrieve "title" property,Why this happens(i want to lazy load of "property")? It seems when i load one of Blob property ,Hibernate loads all of them.Why?(This is my main question)
2.Why Hibernate generates two queries for retrieving only "summary" property of news?

Khosro.

© Stack Overflow or respective owner

Related posts about hiberante

Related posts about lazy-loading