The sorting of the DataTable works different with Recordset and List<E>.
If you have a recordset you can sort like this: `sortBy="#{project['project_id']}"`
<p:dataTable value="#{data.projects}" var="project" paginator="true" rows="10" paginatorPosition="top">
<p:column sortBy="#{project['project_id']}" headerText="Projekt-Nr.">
<h:outputText value="#{project['project_id']}" />
</p:column>
If you have List<E> it works like Daniel said: `sortBy="project_id"`
You have directly access to your properties in the list.
<p:dataTable value="#{data.projects}" var="project" paginator="true" rows="10" paginatorPosition="top">
<p:column sortBy="project_id" headerText="Projekt-Nr.">
<h:outputText value="#{project.project_id}" />
</p:column>
I think they have diffrence because of the structur.
RS:`Recordset project = new Recordset(["project_id", "projectname", ...]`
List: `List<project>`
--> Project class: project_id, procjetname with getter and setter classes.
