Unable to update my database table after editing cell from UI dataTable

Question

Here is my java code to update database table and editing cell from UI.

From UI for caption column to edit its fine but its not updating column values in database table.

public void onCellEdit(CellEditEvent event) {
    System.out.println("inside cell edit");

     UIColumn col=(UIColumn) event.getColumn();
    DataTable o = (DataTable) event.getSource();
    Object oldValue = event.getOldValue();
    Object newValue = event.getNewValue();
    LabelsVO info = (LabelsVO) o.getRowData();
    int newModel = info.getLang_no();
    int newData=info.getLabel_no();

    System.out.println("row index in event method " + event.getRowIndex());
    System.out.println("old value" + oldValue);
    System.out.println("new value" + newValue);
    System.out.println("column1 :" + col.getHeader());

    try {
        conn=Database.getConnection();
        stmt = conn.prepareStatement("update ias_labels set caption_det =? where lang_no =? and label_no=?");
        stmt.setInt(1, newModel);
        stmt.setInt(2, newData);
        stmt.setString(3, newValue.toString());
        int rset = stmt.executeUpdate();
        conn.commit();
        if (rset != 0) {
            System.out.println("updated!!!");
        } else {
            System.out.println("not updated!!!");
        }

    } catch (Exception e) {
        e.printStackTrace();
    }

    if (newValue != null && !newValue.equals(oldValue)) {
        FacesMessage msg = new FacesMessage(FacesMessage.SEVERITY_INFO, "Cell Changed", "Old: " + oldValue + ", New:" + newValue);
        FacesContext.getCurrentInstance().addMessage(null, msg);
    }

---

here is my front end class

<p:layoutUnit position="center" resizable="true" closable="true" collapsible="true">
                    <p:dataTable id="dataTable" var="lab" value="#{labelsMB.userLogList}" editable="true" editMode="cell"  
                                 paginator="true" rows="10"  
                                 paginatorTemplate="  {FirstPageLink} {PreviousPageLink} {PageLinks} {NextPageLink} {LastPageLink} {RowsPerPageDropdown}"  
                                 rowsPerPageTemplate="5,10,15">  
                        <f:facet name="header">  
                            Labels Details
                        </f:facet>
                        <p:ajax event="cellEdit" immediate="true" listener="#{labelsMB.onCellEdit}" update="dataTable" />

                        <p:column headerText="Caption" sortBy="#{lab.caption_det}" filterBy="#{lab.caption_det}" width="40">  
                            <p:cellEditor>
                                <f:facet name="output">
                                    <h:outputText value="#{lab.caption_det}"/>
                                </f:facet>
                                <f:facet name="input">
                                    <h:inputText value="#{lab.caption_det}" style="width:96%"/>
                                </f:facet>
                            </p:cellEditor>
                            </p:column>

                        <p:column sortBy="#{lab.label_no}" filterBy="#{lab.label_no}" width="10">  
                            <f:facet name="header">  
                                <h:outputText value="Label No" />  
                            </f:facet>  
                            <h:outputText value="#{lab.label_no}" />  
                        </p:column>  
                        <p:column sortBy="#{lab.lang_no}" filterBy="#{lab.lang_no}" width="10">  
                            <f:facet name="header">  
                                <h:outputText value="Langauge No" />  
                            </f:facet>  
                            <h:outputText value="#{lab.lang_no}" /> 
                        </p:column> 
                        <p:column sortBy="#{lab.lang_name}" filterBy="#{lab.lang_name}" width="10">  
                            <f:facet name="header">  
                                <h:outputText value="Langauge Name" />  
                            </f:facet>  
                            <h:outputText value="#{lab.lang_name}" /> 
                        </p:column> 
                        <f:facet name="footer">
                            <p:commandButton id="dataTable" icon="ui-icon-disk" iconPos="left" ajax="false" value="Save" action="#{labelsMB.onCellEdit(event)}" />
                        </f:facet>
                    </p:dataTable>