Question

Hi Can anyone help me create a criteria base on the following information.
Basically this code will be added to a function that returns the number of found rows with
the number of child rows greater than 10. The value 10 will be dynamic.

I have been stuck with this problem for a day already and need some help.

Note that I can not control the database itself so I can not use views or change the database schema. Also this is a simplified version of the problem other properties of client and mapfields are omitted and the creation of the projections and criteria will be refactored to a generic helper method.

public class client
{
private int id;
private string code;
@OneToMany(fetch=FetchType.Lazy)
@JoinColumn(name="code", nullable=true)
private List <MapFields> mapFields;
}

public class MapFields
{
private int id;
private string code;
}

How can I do this sql query using hibernate criteria.

SELECT COUNT(*)
FROM 
(
    SELECT MapFields.code
    FROM Client LEFT JOIN MAPFields on Client.code
    GROUP BY MapFields.code
    HAVING COUNT(MapField.code) > 10
) AS A

I have tried the following but to no avail. I keep encountering an exception that tell me that a property can not be resolved.

org.hibernate.QueryException: could not resolve property: numberOfMapFields of: …Client

Criteria criteria = getCurrentSession().createCriteria(Client.class)

criteria.createAlias("mapFields", "mapFields", CriteriaSpecification.Left_Join)

ProjectionList pl = Projections.projectionList();

pl.add(Projections.count("mapFields.code", "numberOfMapFields"));

pl.add(Projections.rowCount());

criteria.setProjection(projectionList);

criteria.add(Restriction.ge("numberOfMapFields", "10"))

criteria.list();

PLEASE can anyone provide a code snippet on how to do this using hibernate criteria and if you need more information just tell me and i will try to provide more information.

Answer 1

selects in the from clause are not supported by criteria. either use hql or sql – Firo

Doh! Thanks for the information…