Aggregate functions (max)

gan.gary · **Joined:** Tue Jun 17, 2008 12:14 am **Posts:** 21

I am new to Hibernate, and I have an XML:

Code:

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
   "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
   "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
  <class name="com.flextronics.flexflow.LuJIG" table="luJIG">
      <id name="id" type="int">
            <column name="ID" />
        </id>
        <property name="description" type="string">
            <column name="Description" length="200" />
        </property>
  </class>
</hibernate-mapping>

why I do something like:

Code:

result = session.createQuery("Select max(lj.id) from LuJIG lj")
.setString(0, strFixture)
.list();
if (result.size() > 0) {  
                    
 }

will hit erorr:

Quote:

java.lang.IllegalArgumentException: No positional parameters in query: Select max(lj.id) from LuJIG lj
at org.hibernate.impl.AbstractQueryImpl.setParameter(AbstractQueryImpl.java:332)
at org.hibernate.impl.AbstractQueryImpl.setString(AbstractQueryImpl.java:457)

Cameron McKenzie · **Posted:** Tue Jun 17, 2008 4:04 pm

This is typically used to set the value for a placeholder:

setString(0, strFixture)

I can't see the 0th element you are setting?

A typical use of variable injection might be something like this:

Code:

Session session = HibernateUtil.beginTransaction();
String loginName = "mj";
String hql="from User where loginName = :name";
Query query = session.createQuery(hql);
query.setString("name", loginName);
Object o = query.uniqueResult();
User user = (User)o;
System.out.println(user.getLoginName());
HibernateUtil.commitTransaction();

Take a look here for some simple Hibernate3 tutorials and information on how to use HQL variable injection queries, if that's what you need:

http://jpa.ezhibernate.com/Javacode/learn.jsp?tutorial=08masteringhqlandnamedqueries

Cameron McKenzie · **Posted:** Tue Jun 17, 2008 4:08 pm

This is typically used to set the value for a placeholder:

setString(0, strFixture)

I can't see the 0th element you are setting?

A typical use of variable injection might be something like this:

Code:

Session session = HibernateUtil.beginTransaction();
String loginName = "mj";
String hql="from User where loginName = :name";
Query query = session.createQuery(hql);
query.setString("name", loginName);
Object o = query.uniqueResult();
User user = (User)o;
System.out.println(user.getLoginName());
HibernateUtil.commitTransaction();

Take a look here for some simple Hibernate3 tutorials and information on how to use HQL variable injection queries, if that's what you need:

http://jpa.ezhibernate.com/Javacode/learn.jsp?tutorial=08masteringhqlandnamedqueries

ramnath · **Posted:** Wed Jun 18, 2008 10:12 am

What is that 0th???

result = session.createQuery("Select max(lj.id) as luJIGid from LuJIG lj")
.list();

or
List results = session.createCriteria(LuJIG.class)
.setProjection( Projections.projectionList()
.add( Projections.max("id") )
)
.list();

Hope this helps:-) Else post more info on the 0th???

gan.gary · **Joined:** Tue Jun 17, 2008 12:14 am **Posts:** 21

Thanks ramnath & Cameron McKenzie. I think there's no param at 0 th position. I just totally new to hsql, especially on aggregate. I will try.

Cameron McKenzie · **Posted:** Thu Jun 19, 2008 9:12 am

0th is the element between -1th and 1th.

:)