3 Replies Latest reply on Feb 16, 2006 11:10 PM by gus888

Help for Entity Query

gus888 Feb 15, 2006 11:17 PM

Hi Folks,

I am new in EJB, and have a question about how to load a null parent_id into its Entity bean. I have a table as follows:
CATEGORY

+---+---------+----------+
|ID |NAME |PARENT_ID |
|1 |Computer |Null |
|2 |PC |1 |
|3 |Mac |1 |

I want to load the first computer row with null parent_id into entity bean Category, but I don't know how to create an em.createQuery("..."). Any help will be appreciated. Thank you in advance.

GUS

1. Re: Help for Entity Query

gus888 Feb 15, 2006 11:32 PM (in response to gus888)

Sorry, I forgot post my entity bean:

@Entity
@Table(name="CATEGORY")
public class Category implements Serializable {

 private long id;

 private String name;

 private Category parentCategory;

 private List<Category> childCategories;
 ....
}

2. Re: Help for Entity Query

epbernard Feb 16, 2006 5:08 AM (in response to gus888)

from Category c where c.parent.id is null
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3. Re: Help for Entity Query

gus888 Feb 16, 2006 11:10 PM (in response to gus888)

Thank you very much, Emmanuel. That is really good help.

GUS
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