如何在Visualforce页面上显示聚合SOQL查询的结果？

Question

我是Visualforce的新手.

我在这里看这个页面:http://force.siddheshkabe.co.in/2010/11/displaying-aggregate-result-on.html

所以,当我将此代码添加到VisualForce页面时:

  AggregateResult[] groupedResults  = [SELECT Name, Days__c FROM Contact WHERE Days__c != ];

  for (AggregateResult ar : groupedResults)  {
    System.debug('Name: ' + ar.get('Name') + '\nDays Taken : ' + ar.get('Days__c') + '\n');

但它只是打印代码而不是执行它.我该怎么办？谢谢你的指导.

Answer 1

Apex代码进入自定义控制器或控制器扩展.VisualForce页面是与控制器分开的文件.您引用的页面未显示VF页面.另外,我认为你不能绑定VF组件AggregateResult,所以你需要一个包装类.

这是一些有效的代码.

控制器:

public with sharing class TestController {

    public Summary[] Summaries { get; set; }

    public TestController() {
        AggregateResult[] results = [
            SELECT Name, Count(Id) Quantity FROM Opportunity GROUP BY Name
        ];
        Summaries = new List<Summary>();
        for (AggregateResult ar : results) {
            Summaries.add(new Summary(ar));
        }
    }

    // wrapper class to hold aggregate data
    public class Summary {
        public Integer Quantity { get; private set; }
        public String Name { get; private set; }

        public Summary(AggregateResult ar) {
            Quantity = (Integer) ar.get('Quantity');
            Name = (String) ar.get('Name');
        }
    }

}

VF页面:

<apex:page controller="TestController">
    <apex:form >
        <apex:repeat value="{!Summaries}" var="summary">
            {!summary.Name}: {!summary.Quantity}<br/>
        </apex:repeat>
    </apex:form>
</apex:page>