p:commandButton in the second datatable doesn't work - jsf

Question

I have two datatables in the same page. The first one is loaded when the page loads. The second one is loaded when a row is clicked. I have a command button in each row. In the first datatable works fine. But, in the second one, the parameter value is null. It only works if I use immediate attribute equals true. Does someone know why?
My page:
<h:form id="form">
<p:dataTable id="dtOwner" selectionMode="single" var="owner" value="#{ownerBean.retornaOwners}"
selection="#{ownerBean.ownerSelected}" rowKey="#{owner.id_owner}">
<p:ajax update="form:pgCars" process="#form" event="rowSelect" listener="#{ownerBean.onRowSelect}" />
<p:column headerText="Actions">
<p:commandButton value="Exclude" actionListener="#{ownerBean.excludeOwner(owner)}"></p:commandButton>
</p:column>
<p:column headerText="Name">
<h:outputText value="#{owner.name}"></h:outputText>
</p:column>
<p:column headerText="Surname">
<h:outputText value="#{owner.surname}"></h:outputText>
</p:column>
</p:dataTable>
<p:panelGrid id="pgCars">
<p:dataTable id="dtCars" var="car" value="#{ownerBean.ownerSelected.listCars}"
selection="#{ownerBean.ownerSelected}" rowKey="#{owner.id_owner}">
<p:column headerText="Actions" >
<p:commandButton value="Exclude" process="#all" update="form" actionListener="#{ownerBean.excludeCar(car)}"></p:commandButton>
</p:column>
<p:column headerText="id_Car" >
<h:outputText value="#{car.id_car}"></h:outputText>
</p:column>
<p:column headerText="id_owner" >
<h:outputText value="#{car.id_owner}"></h:outputText>
</p:column>
<p:column headerText="tipo_carro" >
<h:outputText value="#{car.tipo_carro}"></h:outputText>
</p:column>
<p:column headerText="modelo_carro" >
<h:outputText value="#{car.modelo_carro}"></h:outputText>
</p:column>
</p:dataTable>
</p:panelGrid>
</h:form>
My bean:
package com.tutorial;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import javax.faces.application.FacesMessage;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.ManagedProperty;
import javax.faces.bean.SessionScoped;
import javax.faces.context.FacesContext;
import org.primefaces.event.SelectEvent;
#ManagedBean(name="ownerBean")
#SessionScoped
public class OwnerBean {
#ManagedProperty(value = "#{ownerDAO}")
private OwnerDAO ownerDAO;
public void setOwnerDAO(OwnerDAO ownerDAO) {
this.ownerDAO = ownerDAO;
}
private Owner ownerSelected;
public void excludeOwner(Owner owner) {
System.out.println("Excluding " + owner.getName());
}
public void excludeCar(Car car) {
System.out.println("Excluding car " + car.getModelo_carro());
}
public void onRowSelect(SelectEvent event) {
FacesMessage msg = new FacesMessage("Owner Selected", Integer.toString(
( (Owner) event.getObject()).getId_owner()));
FacesContext.getCurrentInstance().addMessage(null, msg);
ownerSelected = (Owner) event.getObject();
ownerSelected.setListCars(new ArrayList<Car>());
ownerSelected.setListCars(ownerDAO.getCars(ownerSelected));
}
public List<Owner> getRetornaOwners() {
List<Owner> list = new ArrayList<>();
try {
list = ownerDAO.getOwners();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return list;
}
public Owner getOwnerSelected() {
return ownerSelected;
}
public void setOwnerSelected(Owner ownerSelected) {
this.ownerSelected = ownerSelected;
}
}
The excludeOwner(Owner owner) function works fine, but the excludeCars(Car car) doesn't. I always get null in car value.
Thanks

Answer 1

I use process="#this" in the commandButton and works. Also, I remove update attribute from commandButton and process attribute from ajax. Thanks a lot
Ajax:
<p:ajax update="form:dtCars" event="rowSelect" listener="#{ownerBean.onRowSelect}" />
Command button:
<p:commandButton value="Exclude" process="#this" actionListener="#{ownerBean.excludeCar(car)}"></p:commandButton>