what's wrong with this HQL query?

问题

I'm executing the following HQL query in my Grails app:

def maxIndex = VirtualSubOrder.find(
    'select max(vso.index) from VirtualSubOrder vso where vso.virtualOrder = ?', 
    [virtualOrder])

The VirtualSubOrder class definitely has an (Integer) index property and a virtualOrder property.

When I try to execute the query above I get the error:

org.codehaus.groovy.grails.orm.hibernate.exceptions.GrailsQueryException: Invalid query [select max(vso.index) from VirtualSubOrder vso where vso.virtualOrder = ?] for domain class [class com.example.VirtualSubOrder]

回答1:

I believe you want to use VirtualSubOrder.executeQuery() instead of find(). find is for returning domain instances and executeQuery is for arbitrary HQL.

来源：https://stackoverflow.com/questions/13747950/whats-wrong-with-this-hql-query