<h:dataTable> problem with present datas on JSF page

Question

I have small problem with view datas in h:dataTable item. I have native query which is working properly in database and in java:

SELECT SUM(price_list.first_class_price), SUM(price_list.second_class_price)
FROM price_list, connections
WHERE connections.id = price_list.id_connect
GROUP BY connections.source;  

The method in EJB returns a List of elements. This method looks like this:

public List<PriceList> getFirstClassPrices() { 
    Query q = em.createNativeQuery("SELECT SUM(price_list.first_class_price), SUM(price_list.second_class_price) FROM price_list, connections WHERE connections.id = price_list.id_connect GROUP BY connections.source"); 
    return q.getResultList(); 
}  

I want to show result of this query in dataTableItem, but I don`t know how to get to this values. I tried to do something like this (FCP is the method in JSF ManagedBean that returns mentioned list):

<h:dataTable value="#{priceList.FCP}}" var="item" cellspacing="0" cellpadding="1" border="1"> 
<h:column> 
<f:facet name="header"> 
<h: outputText value="First class"/> 
</f:facet> 
<h: outputText value="#{item}"/> 
</h:column> 
<h:column> 
<f:facet name="header"> 
<h: outputText value="Second class"/> 
</f:facet> 
<h: outputText value="#{item}"/> 
</h:column> 
</h:dataTable> 

but this shows me only references as the result in table.

FCP method in JSF ManagedBean looks like this:

public List<PriceList> getFCP() { 
    return priceListFacade.getFirstClassPrices(); 
} 

This solution is working properly when I have a query like this:

SELECT SUM(price_list.first_class_price) 
FROM price_list, connections 
WHERE connections.id = price_list.id_connect
GROUP BY connections.source;

with one SUM element. Then correct datas are in the table and there is no problem.

My question is: how to get datas, no references from the result list when I have two or more SUM elements in a query?

I tried use code like this:

<h:dataTable value="#{priceList.FCP}}" var="item" cellspacing="0" cellpadding="1" border="1"> 
<h:column> 
<f:facet name="header"> 
<h: outputText value="First class"/> 
</f:facet> 
<h: outputText value="#{item.first_class_price}"/> 
</h:column> 
<h:column> 
<f:facet name="header"> 
<h: outputText value="Second class"/> 
</f:facet> 
<h: outputText value="#{item.second_class_price}"/> 
</h:column> 
</h:dataTable> 

but then I have an EJB exception: there is no properties like first_class_price and second_class_price .

I tried to change the query for this:

SELECT SUM(price_list.first_class_price) AS p1, SUM(price_list.second_class_price) AS p2 
FROM price_list, connections 
WHERE connections.id = price_list.id_connect
GROUP BY connections.source; 

and then in JSF I used a code like this:

<h:dataTable value="#{priceList.FCP}}" var="item" cellspacing="0" cellpadding="1" border="1"> 
<h:column> 
<f:facet name="header"> 
<h: outputText value="First class"/> 
</f:facet> 
<h: outputText value="#{item.p1}"/> 
</h:column> 
<h:column> 
<f:facet name="header"> 
<h: outputText value="Second class"/> 
</f:facet> 
<h: outputText value="#{item.p2}"/> 
</h:column> 
</h:dataTable> 

but I have the same EJB exception that properties p1 and p2 doesn't exists.

I am new in Java EE and I can't handle with this. Maybe there is another way to solve my problem? Maybe I shouldn't use h:dataTableItem ?

Thanks for your replies.

Answer 1

I have found a solution of my problem on the other topic. Here is the right solution:

SessionBean:

public List<Object[]> getFirstClassPrices() {
    Query q = em.createNativeQuery("SELECT SUM(price_list.first_class_price), "
            + "SUM(price_list.second_class_price), SUM(price_list.third_class_price), "
            + "SUM(price_list.luggage_fee), SUM(price_list.airport_fee), SUM(price_list.fuel_fee), "
            + "SUM(price_list.crew_salary), connections.source FROM price_list, connections WHERE connections.id = price_list.id_connect GROUP BY connections.source");
    List<Object[]> lista = q.getResultList();
    return lista;
}

JSF ManagedBean:

public List<Object[]> getFCP() {   
    return priceListFacade.getFirstClassPrices();
}

and finally fragment of JSF page:

<h:outputText value="#{item[0]}"/>

Answer 2

I got stuck when trying to use "GROUP BY" query in my application. Solution I used is following:

1, tableNamefacade.java:

public List<Object[]> getAllGroupByCoulumn() {
  Query q = em.createNativeQuery("SELECT d.column FROM tableName d GROUP BY d.coulmn");
  List<Object[]> list = q.getResultList();
  return list;
}

2, tableNameController.java: property of bean:

private List<Object[]> items;

and function, which prepare list that is displayed at xhtml page:

 items = getFacade().getAllGroupByCoulumnm(); 

3, finaly the dataTable in xhtml page:

<h:dataTable value="#{myController.items}" var="item">
  ...
     <h:outputText value="#{item}">
  ...