salesforce 零基础学习（二十三）数据记录导出至excel（自定义报表导出）

我们都知道，报表有个功能为导出excel，但是有的时候客户需求往往标准的报表达不到，比如导出excel，其中本月修改的数据字段标红，如下图所示。

这就需要我们去写VF来实现此功能。

需求：将数据表记录导出成excel，其中excel内容需要本月修改的数据字段自动标红显示。

表：Goods__c，字段如下：

设计思路：如果导出excel并且需要跟踪每个字段的修改时间进行校验是否标红，则需要有一个表取跟踪这个表.有两种方式进行Track。

1.salesforce中提供了Track History功能，即当表字段小于20个情况下，可以通过设置Track History，那样系统会自动创建相关表的History表，在这个demo中系统会自动创建Goods_History表。详细Track History知识可以参看以下链接：

https://help.salesforce.com/apex/HTFederatedSearchResults#q=Track%20History&t=TopResultTab&sort=relevancy&f:@sflanguage=[en_US]

2.当表的字段超过20个，则通过Track History便无法满足需求了，这种情况我们需要自己创建一个sObject来和需要track的sObject进行关联，如下图所示：

页面显示均使用标准生成的页面，在Goods__c修改情况下，需要设置Trigger自动插入此条Goods__c记录对应的GoodsSign__c记录，如果某个字段有修改，则设置某个字段相对应的Date信息为System.today().

制作步骤：

1.写GoodsTrigger.Trigger代码如下所示：

 trigger GoodsTrigger on Goods__c (before delete, before update) {
     if(trigger.isBefore) {
         //get the Schema Information of GoodsSign to check whether current user has access to operate the data
         Schema.DescribeSObjectResult goodsSignDescribe = GoodsSign__c.sObjectType.getDescribe();
         List<GoodsSign__c> goodsSignList = new List<GoodsSign__c>();
         //第一个参数为Goods__c的ID，第二个参数为GoodsSign__c
         Map<ID,GoodsSign__c> goodsIdToGoodsSignMap = new Map<ID,GoodsSign__c>();
         if(trigger.isUpdate) {
             Set<ID> goodsIdSet = new Set<ID>();
             if(goodsSignDescribe.isCreateable() && goodsSignDescribe.isUpdateable()) {
                 List<Goods__c> goodsNewList = trigger.new;
                 List<Goods__c> goodsOldList = trigger.old;
                 for(Goods__c goods : goodsNewList) {
                     goodsIdSet.add(goods.Id);
                 }
                 String fetchGoodsSignByGoodsId = 'SELECT CreatedById, CreatedDate,' +
                     ' IsDeleted, GoodsBrandDate__c, GoodsCostPriceDate__c,' +
                     ' GoodsDescribeDate__c, GoodsId__c, GoodsNameDate__c,' +
                     ' GoodsPriceDate__c, Name, LastModifiedById, LastModifiedDate,' +
                     ' OwnerId, Id, SystemModstamp FROM GoodsSign__c ' +
                     ' where GoodsId__c in :goodsIdSet';
                 List<GoodsSign__c> tempGoodsSignList = Database.query(fetchGoodsSignByGoodsId);
                 for(GoodsSign__c goodsSign : tempGoodsSignList) {
                     goodsIdToGoodsSignMap.put(goodsSign.GoodsId__c,goodsSign);
                 }
                 for(Integer i=0;i<goodsNewList.size();i++) {
                     Goods__c goodsNew = goodsNewList.get(i);
                     Goods__c goodsOld = goodsOldList.get(i);
                     GoodsSign__c goodsSign = new GoodsSign__c();
                     Id goodsId = goodsNew.Id;
                     if(goodsIdToGoodsSignMap.get(goodsId) != null) {
                         goodsSign = goodsIdToGoodsSignMap.get(goodsId);
                     }

                     if(goodsNew.GoodsName__c != goodsOld.GoodsName__c) {
                         goodsSign.GoodsNameDate__c = System.today();
                     }
                     if(goodsNew.GoodsPrice__c != goodsOld.GoodsPrice__c) {
                         goodsSign.GoodsPriceDate__c = System.today();
                     }
                     if(goodsNew.GoodsCostPrice__c != goodsOld.GoodsCostPrice__c) {
                         goodsSign.GoodsCostPriceDate__c = System.today();
                     }
                     if(goodsNew.GoodsBrand__c != goodsOld.GoodsBrand__c) {
                         goodsSign.GoodsBrandDate__c = System.today();
                     }
                     if(goodsNew.GoodsDescribe__c != goodsOld.GoodsDescribe__c) {
                         goodsSign.GoodsDescribeDate__c = System.today();
                     }
                     if(goodsSign.GoodsId__c == null) {
                         goodsSign.GoodsId__c = goodsId;
                     }
                     goodsSignList.add(goodsSign);
                  }
                  if(goodsSignList.size() > 0) {
                      upsert goodsSignList;
                  }
             }

         } else if(trigger.isDelete) {
             //cascade delete
             if(goodsSignDescribe.isDeletable()) {
                 List<Goods__c> goodsList = trigger.old;
                 Set<ID> goodsIdSet = new Set<ID>();
                 for(Goods__c currentGoods : goodsList) {
                     if(!goodsIdSet.contains(currentGoods.Id)) {
                         goodsIdSet.add(currentGoods.Id);
                     }
                 }
                 String fetchGoodsSignByGoodsIdSet = 'SELECT CreatedById, CreatedDate,' +
                 ' IsDeleted, GoodsBrandDate__c, GoodsCostPriceDate__c, GoodsDescribeDate__c,' +
                 ' GoodsId__c, GoodsNameDate__c, GoodsPriceDate__c, Name, LastModifiedById,' +
                 ' LastModifiedDate, OwnerId, Id, SystemModstamp FROM GoodsSign__c' +
                 ' where GoodsId__c in :goodsIdSet';
                 List<GoodsSign__c> goodsSignNeedDeleteList = Database.query(fetchGoodsSignByGoodsIdSet);
                 delete goodsSignNeedDeleteList;
             }
         }
     }
 }

此Trigger有两个功能：

1.当进行修改操作并且Goods__c记录有字段改变时，如果有相对应的GoodsSign__c进行对应，则update此记录，否则新建记录，并记录哪些字段有修改;

2.当进行删除操作时，如果有相对应的GoodsSign__c进行对应，则级联删除。

两者操作均需要当前用户有GoodsSign的操作权限。

2.新建一个类用来记录导出的字段以及导出的字段的颜色。

 public with sharing class GoodsExportObject {
     public String goodsName{get;set;}
     public String goodsNameColor{get;set;}
     public String goodsBrand{get;set;}
     public String goodsBrandColor{get;set;}
     public String goodsPrice{get;set;}
     public String goodsPriceColor{get;set;}
     public String goodsCostPrice{get;set;}
     public String goodsCostPriceColor{get;set;}
     public String goodsDescribe{get;set;}
     public String goodsDescribeColor{get;set;}
 }

3.新建Controller，此Controller用来获取显示到excel的数据。

 public with sharing class ExportGoodsController {

     List<Goods__c> goodsList{get;set;}
     List<GoodsSign__c> goodsSignList{get;set;}
     public List<GoodsExportObject> exportGoodsList{get;set;}
     Map<Id,GoodsSign__c> goodsSignMap = new Map<Id,GoodsSign__c>();
     public ExportGoodsController() {
         goodsList = new List<Goods__c>();
         goodsSignList = new List<GoodsSign__c>();
         exportGoodsList = new List<GoodsExportObject>();
         String fetchAllGoods = 'SELECT CreatedById, CreatedDate, IsDeleted,' +
         ' Name, GoodsBrand__c, GoodsCostPrice__c, GoodsDescribe__c, GoodsName__c,' +
         ' GoodsPrice__c, LastActivityDate, LastModifiedById, LastModifiedDate,' +
         ' OwnerId, Id, SystemModstamp FROM Goods__c';
         goodsList = Database.query(fetchAllGoods);
         String fetchAllGoodsSign = 'SELECT CreatedById, CreatedDate, IsDeleted,' +
         ' GoodsBrandDate__c, GoodsCostPriceDate__c, GoodsDescribeDate__c,' +
         ' GoodsId__c, GoodsNameDate__c, GoodsPriceDate__c, Name, LastModifiedById,' +
         ' LastModifiedDate, OwnerId, Id, SystemModstamp FROM GoodsSign__c';
         goodsSignList = Database.query(fetchAllGoodsSign);
         for(GoodsSign__c goodsSign : goodsSignList) {
             if(!goodsSignMap.containsKey(goodsSign.GoodsId__c)) {
                 goodsSignMap.put(goodsSign.GoodsId__c,goodsSign);
             }
         }
     }

     public PageReference exportGoods() {
         String bgColor = 'red';
         Integer nowMonth = System.today().month();
         for(Goods__c currentGoods : goodsList) {
             GoodsSign__c goodsSign = goodsSignMap.get(currentGoods.Id);
             GoodsExportObject tempGoodsExportObject = new GoodsExportObject();
             tempGoodsExportObject.goodsName = currentGoods.GoodsName__c;
             tempGoodsExportObject.goodsBrand = currentGoods.GoodsBrand__c;
             tempGoodsExportObject.goodsPrice = String.valueOf(currentGoods.GoodsPrice__c);
             tempGoodsExportObject.goodsCostPrice = String.valueOf(currentGoods.GoodsCostPrice__c);
             tempGoodsExportObject.goodsDescribe = currentGoods.GoodsDescribe__c;
             if(goodsSign != null) {
                 if(goodsSign.GoodsNameDate__c != null && goodsSign.GoodsNameDate__c.month() == nowMonth) {
                     tempGoodsExportObject.goodsNameColor = bgColor;
                 }
                 if(goodsSign.GoodsBrandDate__c != null && goodsSign.GoodsBrandDate__c.month() == nowMonth) {
                     tempGoodsExportObject.goodsBrandColor = bgColor;
                 }
                 if(goodsSign.GoodsPriceDate__c != null && goodsSign.GoodsPriceDate__c.month() == nowMonth) {
                     tempGoodsExportObject.goodsPriceColor = bgColor;
                 }
                 if(goodsSign.GoodsCostPriceDate__c != null && goodsSign.GoodsCostPriceDate__c.month() == nowMonth) {
                     tempGoodsExportObject.goodsCostPriceColor = bgColor;
                 }
                 if(goodsSign.GoodsDescribeDate__c != null && goodsSign.GoodsDescribeDate__c.month() == nowMonth) {
                     tempGoodsExportObject.goodsDescribeColor = bgColor;
                 }
             }
             exportGoodsList.add(tempGoodsExportObject);
         }

         return new PageReference('/apex/ExportGoodsPage');
     }

 }

4.新建显示的VF页面

IsExportPage.page:此VF页面用于显示一个按钮，当点击按钮后，执行Excel生成操作。

 <apex:page controller="ExportGoodsController">
 <apex:form >
 <apex:commandButton action="{!exportGoods}" value="exportGoods"/>
 </apex:form>
 </apex:page>

ExportGoodsPage:生成Excel

 <apex:page controller="ExportGoodsController" cache="true" contenttype="application/x-excel# GenExcel.xls" showheader="false">
 <head>
     <meta http-equiv="Content-Type" content="text/html;charset=UTF-8" />
 </head>
 <apex:dataTable value="{!exportGoodsList}" var="exportGoods" border="1">
         <apex:column style="background:{!exportGoods.goodsNameColor};">
             <apex:facet name="header">Goods Name </apex:facet>
             {!exportGoods.goodsName}
         </apex:column>
         <apex:column style="background:{!exportGoods.goodsBrandColor};">
             <apex:facet name="header">Goods Brand</apex:facet>
             {!exportGoods.goodsBrand}
         </apex:column>
         <apex:column style="background:{!exportGoods.goodsPriceColor};">
             <apex:facet name="header">Goods Price</apex:facet>
             {!exportGoods.goodsPrice}
         </apex:column>
         <apex:column style="background:{!exportGoods.goodsCostPriceColor};">
             <apex:facet name="header">Goods Cost Price</apex:facet>
             {!exportGoods.goodsCostPrice}
         </apex:column>
         <apex:column style="background:{!exportGoods.goodsDescribeColor};">
             <apex:facet name="header">Goods Describe</apex:facet>
             {!exportGoods.goodsDescribe}
         </apex:column>
     </apex:dataTable>
 </apex:page>

5.配置Button,并显示到列表页面上。

结果样式显示：

点击Goods Reports按钮，跳转到导出 记录的按钮页面

点击exportGoods则可以生成Excel。以下为Excel的生成界面，其中红色为修改的记录字段。

总结：上述demo只是演示当字段Tracking超过20个需要额外创建表的情况处理，当小于20个情况下可以直接通过History的表进行查询，有兴趣的可以自己尝试，生成页面因为使用DataTable，所以对于导出的记录行数有要求，必须不大于1000条，超过则应该会报Error。篇中如果有写的错误的地方欢迎指出，如果有疑问地方欢迎留言，转载请注明出处。