在Salesforce中，常常要对各种数据进行处理，已满足业务逻辑。本篇文章会介绍如何实现从object获取数据，然后将取得的数据进行一系列简单处理。

第一步：SongName__c 是一个新建的object，向SongName__c  object中插入数据：

/*向表SongName__c插入101条数据*/
    public List<SongName__c> CreateData(){
        List<SongName__c> songName = new List<SongName__c>();
        for(Integer i=0; i<101; i++){
           SongName__c a = new SongName__c(Song__c = '歌曲' + i,Contact_email__c ='wicky@sina.com',password__c ='19920122', usage__c = i+100, Active__c = true);
           songName.add(a);
       }

        try{
        insert songName;
    }
        catch(DmlException e){
            System.debug('An unexpected error has occurred'+e.getMessage());
    }
        SongName = [Select usage__c FROM SongName__c Where CreatedDate>=2016-10-22T00:00:00+08:00
                   and CreatedDate<=2016-10-27T00:00:00+08:00 ];

        system.debug('插入SongName__c的数据========================'+SongName);
        return SongName;

}    

打印出SongName__c object中的usage__c字段： 

14:02:31.2 (505595323)|USER_DEBUG|[59]|DEBUG|......SongName__c.........========================(SongName__c:{usage__c=100, Id=a002800000rlMrEAAU}, SongName__c:{usage__c=101, Id=a002800000rlMrFAAU}, SongName__c:{usage__c=102, Id=a002800000rlMrGAAU}, SongName__c:{usage__c=103, Id=a002800000rlMrHAAU}, SongName__c:{usage__c=104, Id=a002800000rlMrIAAU}, SongName__c:{usage__c=105, Id=a002800000rlMrJAAU}, SongName__c:{usage__c=106, Id=a002800000rlMrKAAU}, SongName__c:{usage__c=107, Id=a002800000rlMrLAAU}, SongName__c:{usage__c=108, Id=a002800000rlMrMAAU}, SongName__c:{usage__c=109, Id=a002800000rlMrNAAU}, ...)

 

 

第二步：从 SongName__c 表中获得usage__c 字段（Decimal）的值，并调用快速排序方法将usage__c 字段的值从小到大排序。

/*从Object SongName__c 获得数据,并将获取结果排序*/    
    public List<Decimal> getData(){
        List<SongName__c>  SongName=CreateData();

        Map<Id, Decimal> SongNameMap = new Map<Id, Decimal>();
        for (SongName__c sn: SongName ){
            SongNameMap.put(sn.id, sn.usage__c);
        }

        Set <Id> SongNameKey = new Set<Id>();
        List<Decimal> songnameva lue = new List<Decimal>(); 
        SongNameKey = SongNameMap.keyset();
        for(String key: SongNameKey){
            songnameva lue.add(SongNameMap.get(key));
        }       
        system.debug('GET的数据是======================='+songnameva lue);
        Quicksort.sortStatic(songnameva lue);
        system.debug('排序结果======================='+songnameva lue);
        return songnameva lue;
    }

快速排序方法：

public class Quicksort  {
        private List<Decimal> mNumbers;
        private Integer mNumber;
        public static void sortStatic(List<Decimal> values){
          (new Quicksort()).sort(values);
            }//main function
            public void sort(List<Decimal> values) {

              if (values ==null || values.size()==0){
                return;
              }
              this.mNumbers = values;
              mNumber = values.size();
              quicksort(0, mNumber - 1);
            }

            private void quicksort(Integer low, Integer high) {
              Integer i = low, j = high;

              Decimal pivot = mNumbers[low + (high-low)/2];


              while (i <= j) {
                while (mNumbers[i] < pivot) {
                  i++;
                }

                while (mNumbers[j] > pivot) {
                  j--;
                }

                if (i <= j) {
                  exchange(i, j);
                  i++;
                  j--;
                }
              }
              if (low < j)
                quicksort(low, j);
              if (i < high)
                quicksort(i, high);
            }

            private void exchange(Integer i, Integer j) {
              Decimal temp = mNumbers[i];
              mNumbers[i] = mNumbers[j];
              mNumbers[j] = temp;
            }
    }

第三步：取usage__c 中最大的3个值和最小的三个值取平均然后乘以常量，常量会以随机方法生成。将结果插入表CustomerUsage__c 的UsageIn