Datatable not displaying any data but its fine using a pannel grid - jsf

Question

i am currently using a pannel grid to display some data retrived from a database, this is working fine, the layout is not perfect but it displays all of the correct data, however i am wanting to use a datatable for looks more than anything, i have tried to use the outputText from the pannel grid but when i run the page it just says no data found, but on the same page the same code displays the data in the pannel grid
what am i doing wrong ?
this is the code for the working pannel grid
<!-- heading -->
<f:facet name="header">
User Details
</f:facet>
<h:outputText value="#{bundle.ViewUserdetailsLabel_id}"/>
<!-- adding in a small effect here that will fade a message when a user hovers over the id number or username -->
<h:outputLink id="id1" value="#">
<h:outputText id="id" value="#{userdetailsController.selected.id}" title="#{bundle.ViewUserdetailsTitle_id}"/>
</h:outputLink>
<p:tooltip for="id" value="This is your I.D. Number" showEffect="fade" hideEffect="fade" />
<h:outputText value="#{bundle.ViewUserdetailsLabel_username}"/>
<h:outputLink id="username1" value="#">
<h:outputText id="username" value="#{userdetailsController.selected.username}" title="#{bundle.ViewUserdetailsTitle_username}"/>
</h:outputLink>
<p:tooltip for="username" value="Your registered username, this can be changed" showEffect="fade" hideEffect="fade" />
</p:panelGrid>
and here is the not working datatable
<p:dataTable>
<p:column >
<f:facet name="header">
<h:outputText value="{bundle.ViewUserdetailsLabel_id}"/>
</f:facet>
<h:outputText value="{userdetailsController.selected.id}" />
</p:column>
<p:column headerText="username" >
<f:facet name="header">
<h:outputText value="{bundle.ListUserdetailsTitle_username}"/>
</f:facet>
<h:outputText value="{userdetailsController.selected.username}" />
</p:column>
</p:dataTable>
as you can see the outputText values are the same so it should work right ?
thanks

Answer 1

If you happen to have only few hardcoded values to display in a form of a table, then you are better off using <h:panelGrid>. If you however have a list of objects that you want to iterate over and display them quickly then use <p:dataTable>.
Let's say we have a List of employees
<p:dataTable var="employee" value="#{tableBean.employees}">
<p:column headerText="Name">
<h:outputText value="#{employee.name}" />
</p:column>
<p:column headerText="Age">
<h:outputText value="#{employee.age}" />
</p:column>
<p:column headerText="Sex">
<h:outputText value="#{employee.sex}" />
</p:column>
</p:dataTable>
then your table would look like this. var in this case is completely arbitrary, you could for instance call it 'fluffy' if you wanted. There are a lot of settings you can use with dataTable like pagination, export, sorting etc. But I suggest you familiarize yourself with Primefaces showcase