192 words

select(selection) - JPA CriteriaQuery's method

Specify the item that is to be returned in the query result. Replaces the previously specified selection(s), if any.

Note: Applications using the string-based API may need to specify the type of the select item when it results from a get or join operation and the query result type is specified.

     For example:
 
     CriteriaQuery<String> q = cb.createQuery(String.class);
     Root<Order> order = q.from(Order.class);
     q.select(order.get("shippingAddress").<String>get("state"));
 
     CriteriaQuery<Product> q2 = cb.createQuery(Product.class);
     q2.select(q2.from(Order.class)
                 .join("items")
                 .<Item,Product>join("product"));

Parameters:
selection - selection specifying the item that is to be returned in the query result
Returns:
the modified query
Throws:
IllegalArgumentException - if the selection is a compound selection and more than one selection item has the same assigned alias
Since:
JPA 2.0

This documentation page is derived (with some adjustments) from the open source JPA 2 RI (EclipseLink)
and is available under the terms of the Eclipse Public License, v. 1.0 and Eclipse Distribution License, v. 1.0.
Object Relational Mapping (ORM) JPA 2 providers include Hibernate, EclipseLink, TopLink, OpenJPA and DataNucleus.
Object DB is not an ORM JPA implementation but an Object Database for Java with built in JPA 2 support.