如何将记录合并在一起

Question

我能够更新数据库，以便用户保存它的每个部分保存工作正常，在数据库的正确列中，但我现在想要实现的是不是保存到新行，检查那里studentNumber如果它已经在表中有记录（它必须得到这么远）将列更新到该记录而不是开始新记录

我该怎么做？

目前这是我的代码：

这是u.i.他们选择价值并按提交

                            <p:spinner id="ajaxspinner80-100" value="#{editMarkingBean.markSectionTwo.markSectionTwo}"
                                       stepFactor="1"  min="80" max="100" disabled="#{formBean.number != 8}">
                                <p:ajax update="ajaxspinnervalue" process="@this" />
                            </p:spinner>

保存按钮

                    <p:commandButton action="#{editMarkingBean.markSectionTwo}" value="#{bundle.buttonSave}" update=":growl" icon="ui-icon-disk"/>

支持bean是：

@Named(value = "editMarkingBean")
@ViewScoped
public class EditMarkingController {

    private String searchString;
    private String ordering;
    private String criteria;
    private String match;
    private Date today;
    private String caseMatch;
    private int spinnerField;
    private Marking markSectionOne;
    private Marking studentNumber;
    private Marking markSectionTwo;

    private MarkingService markingService;

    private Marking markToEdit;

    @Inject
    private MarkingFacade markingFacade;

    @PostConstruct
    public void init() {
        //this.markToEdit = this.markingFacade.find(studentNumber);
        this.markSectionTwo = new Marking();
    }

    public String markSectionTwo() {
        this.markingFacade.edit(markSectionTwo);
        this.setMessage("Mark Saved");
        markSectionTwo = new Marking();
        this.setMessage("Mark Saved");
        // now navigating to the next page
        return "/lecturer/marking/marking-section-three";
    }

    private void setMessage(String message) {
        FacesContext fc = FacesContext.getCurrentInstance();
        fc.addMessage(null, new FacesMessage(message, ""));
    }

    public Marking getMarkSectionTwo() {
        return markSectionTwo;
    }

    public void setMarkSectionTwo(Marking markSectionTwo) {
        this.markSectionTwo = markSectionTwo;
    }

    public String getSearchString() {
        return searchString;
    }

    public void setSearchString(String searchString) {
        this.searchString = searchString;
    }

    public String getOrdering() {
        return ordering;
    }

    public void setOrdering(String ordering) {
        this.ordering = ordering;
    }

    public String getCriteria() {
        return criteria;
    }

    public void setCriteria(String criteria) {
        this.criteria = criteria;
    }

    public String getMatch() {
        return match;
    }

    public void setMatch(String match) {
        this.match = match;
    }

    public Date getToday() {
        return today;
    }

    public void setToday(Date today) {
        this.today = today;
    }

    public String getCaseMatch() {
        return caseMatch;
    }

    public void setCaseMatch(String caseMatch) {
        this.caseMatch = caseMatch;
    }

    public int getSpinnerField() {
        return spinnerField;
    }

    public void setSpinnerField(int spinnerField) {
        this.spinnerField = spinnerField;
    }

    public Marking getMarkSectionOne() {
        return markSectionOne;
    }

    public void setMarkSectionOne(Marking markSectionOne) {
        this.markSectionOne = markSectionOne;
    }

    public Marking getStudentNumber() {
        return studentNumber;
    }

    public void setStudentNumber(Marking studentNumber) {
        this.studentNumber = studentNumber;
    }

    public MarkingService getMarkingService() {
        return markingService;
    }

    public void setMarkingService(MarkingService markingService) {
        this.markingService = markingService;
    }

    public MarkingFacade getMarkingFacade() {
        return markingFacade;
    }

    public void setMarkingFacade(MarkingFacade markingFacade) {
        this.markingFacade = markingFacade;
    }

}

但目前只将数据的新行添加到数据库，而不是尝试将其与数据库中已包含的数据合并为具有特定学号的学生

我怎样才能做到这一点？谢谢你们的帮助：）

编辑：

我试过了：

 private Marking markToEdit;

    @Inject
    private MarkingFacade markingFacade;

    @PostConstruct
    public void init() {
        this.markToEdit = this.markingFacade.find(studentNumber);
        //this.markSectionTwo = new Marking();
    }

    public String markSectionTwo() {
        this.markingFacade.edit(markSectionTwo);
        this.setMessage("Mark Saved");
       // markSectionTwo = new Marking();
        //this.setMessage("Mark Saved");
        // now navigating to the next page
        return "/lecturer/marking/marking-section-three";
    }

但得到错误：

exception

javax.servlet.ServletException: WELD-000049 Unable to invoke public void sws.control.EditMarkingController.init() on sws.control.EditMarkingController@4109691f
root cause

org.jboss.weld.exceptions.WeldException: WELD-000049 Unable to invoke public void sws.control.EditMarkingController.init() on sws.control.EditMarkingController@4109691f
root cause

java.lang.reflect.InvocationTargetException
root cause

javax.ejb.EJBException
root cause

java.lang.IllegalArgumentException: An instance of a null PK has been incorrectly provided for this find operation.

Answer 1

我使用的方法与您的方法非常相似，但名称不同。我会在这里发布，所以我认为你可以有一些想法。

我的方法是在合并之前明确检查实体。

我的JSF CRUD看起来像这样

XHTML

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
    xmlns:f="http://java.sun.com/jsf/core"
    xmlns:h="http://java.sun.com/jsf/html"
    xmlns:ui="http://java.sun.com/jsf/facelets"
    xmlns:p="http://primefaces.org/ui">
<h:head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
    <title>DataSource Manager</title>
</h:head>
<h:body>
    <h:form id="ds">

        <p:spacer height="10" />
        <p:fieldset legend="Insert/Edit Data Source">
        <p:panel id="insertUpdateForm">
        <h:panelGrid columns="2">

            <p:outputLabel for="name" value="Data Source Name:" style="width:100px;"/>  
            <p:inputText id="name" value="#{dataSourceMB.dataSource.name}"/>


            <p:outputLabel for="user" value="User:" style="width:100px;"/>  
            <p:inputText id="user" value="#{dataSourceMB.dataSource.user}"/>


            <p:outputLabel for="driver" value="Driver:" style="width:100px;"/>  
            <p:inputText id="driver" value="#{dataSourceMB.dataSource.driver}" />

        </h:panelGrid>
        </p:panel>

        <p:panel>
            <p:commandButton value="Save" action="#{dataSourceMB.saveDataSource}" update="dsList,insertUpdateForm" />
            <p:commandButton value="Clear" action="#{dataSourceMB.clearDataSource}" update="insertUpdateForm" />
            <p:commandButton value="Test Connection" action="#{dataSourceMB.testConnection}"/>
        </p:panel>

        </p:fieldset>


        <p:spacer height="10" />
        <p:fieldset legend="Data Sources">    
        <p:panel>
            <p:dataTable 
                var="ds" 
                value="#{dataSourceMB.listDataSources}" 
                paginator="true" rows="10"  
                paginatorTemplate="{RowsPerPageDropdown} {FirstPageLink} {PreviousPageLink} {CurrentPageReport} {NextPageLink} {LastPageLink}"  
                rowsPerPageTemplate="10,50,100"
                id="dsList">  

            <p:column headerText="ID">                
                <h:outputText value="#{ds.id}" />  
            </p:column>
            <p:column headerText="Name">                  
                <h:outputText value="#{ds.name}" />  
            </p:column>
            <p:column headerText="JDBC">                  
                <h:outputText value="#{ds.jdbc} " />  
            </p:column>

            <!-- check http://jqueryui.com/themeroller/ for icons -->             

            <p:column headerText="" style="width:2%">  
                <p:commandButton  icon="ui-icon-pencil" action="#{dataSourceMB.editDataSource}" title="Edit" update=":ds:insertUpdateForm">   
                    <f:setPropertyActionListener value="#{ds}" target="#{dataSourceMB.selectedDataSource}" />  
                </p:commandButton>  
            </p:column>                           
            <p:column headerText="" style="width:2%">  
                <p:commandButton  icon="ui-icon-trash" action="#{dataSourceMB.removeDataSource}" title="Remove" update=":ds:insertUpdateForm,dsList">  
                    <f:setPropertyActionListener value="#{ds}" target="#{dataSourceMB.selectedDataSource}" />  
                </p:commandButton>              
            </p:column>  
            </p:dataTable>
        </p:panel>
        </p:fieldset>
    </h:form>
</h:body>
</html>

我的托管bean

import java.io.Serializable;
import java.util.List;

import javax.annotation.PostConstruct;
import javax.ejb.EJB;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.ViewScoped;

import org.apache.log4j.Logger;

import DataSourceEJB;
import JSFUtilEJB;
import DataSource;

@ManagedBean
@ViewScoped
public class DataSourceMB implements Serializable {

    private static final long serialVersionUID = 871363306742707990L;
    private static Logger log = Logger.getLogger(DataSourceMB.class);

    @EJB
    private JSFUtilEJB jsfUtilEJB;

    @EJB
    private DataSourceEJB dataSourceEJB;

    private DataSource dataSource;
    private DataSource selectedDataSource;
    private List<DataSource> listDataSources;

    @PostConstruct
    public void init() {
        try {
            this.dataSource = new DataSource();
            this.listDataSources = this.dataSourceEJB.listDataSources();
        } catch (Exception e) {
            jsfUtilEJB.addErrorMessage(e,"Could not list");
        }
    }

    public void removeDataSource(){
        try {
            this.dataSourceEJB.removeDataSource(this.selectedDataSource);
            jsfUtilEJB.addInfoMessage("Removed "+this.selectedDataSource.getName());

            if (this.dataSource != null && this.dataSource.getId() != null && this.dataSource.getId().equals(this.selectedDataSource.getId())){
                this.dataSource = null;
            }
            this.listDataSources = this.dataSourceEJB.listDataSources();

        } catch (Exception e) {
            jsfUtilEJB.addErrorMessage(e,"Could not remove");
        }
    }

    public void saveDataSource(){
        try {
            this.dataSourceEJB.saveDataSource(this.dataSource);
            jsfUtilEJB.addInfoMessage("Saved "+this.dataSource.getName());

            this.dataSource = new DataSource();
            this.listDataSources = this.dataSourceEJB.listDataSources();
        } catch (Exception e) {
            jsfUtilEJB.addErrorMessage(e,"Could not save");
        }
    }

    public void editDataSource(){
        this.dataSource = this.selectedDataSource;

    }

    public void clearDataSource(){
        this.dataSource = new DataSource();
    }

    public DataSource getDataSource() {
        return dataSource;
    }

    public void setDataSource(DataSource dataSource) {
        this.dataSource = dataSource;
    }

    public DataSource getSelectedDataSource() {
        return selectedDataSource;
    }

    public void setSelectedDataSource(DataSource selectedDataSource) {
        this.selectedDataSource = selectedDataSource;
    }

    public List<DataSource> getListDataSources() {
        return listDataSources;
    }

    public void setListDataSources(List<DataSource> listDataSources) {
        this.listDataSources = listDataSources;
    }

}

我的EJB

import java.io.IOException;
import java.sql.SQLException;
import java.util.List;

import javax.ejb.Stateless;
import javax.inject.Inject;

import DataSource;

@Stateless
public class DataSourceEJB {

    @Inject
    private BaseService baseService;

    public List<DataSource> listDataSources() {
        return this.baseService.getDataSourceDAO().getAll();
    }


    public void removeDataSource(DataSource ds) throws Exception {
        DataSource a = this.baseService.getDataSourceDAO().find(ds.getId()); 
        this.baseService.getDataSourceDAO().delete(a);      
    }

    public void saveDataSource(DataSource ds) throws Exception {
        DataSource a = this.baseService.getDataSourceDAO().find(ds.getId());
        if (a == null){
            this.baseService.getDataSourceDAO().add(ds);
        }else{
            this.baseService.getDataSourceDAO().edit(ds);
        }       
    }

    public DataSource getById(long id) {
        return this.baseService.getDataSourceDAO().find(id);
    }

    public DataSource getByName(String name) {
        return this.baseService.getDataSourceDAO().findByName(name);
    }

}

DAO

public E find(Long id) {
    return (E)entityManager.find(clazz, id);
}

public void add(E entity) throws Exception {
    entityManager.persist(entity);
}


public E edit(E entity) throws Exception {
    return entityManager.merge(entity);
}


public void delete(E entity) throws Exception {
    entityManager.remove(entity);
}