GROUP BY - Count Method in Apex Controller

Scenario:
Need to do Totals of Stages in Opportunity for the entire org.

Thought Process:

1. What are the columns involved? Answer: StageName and Count or Total
2. What methods will we utilize to achieve these results? Answer: Group By SOQL Statement with Count.
3. What UI to built this neat logic? Answer: Apex Controller and VisualForce Page
4. Need to achieve this type of reporting for the user:

Solution:

1. Use Eclipse IDE or SOQL Explorer to create your SOQL Statement.

2. SELECT StageName, Count(Name) ce 

   FROM Opportunity GROUP BY StageName

3. Second create  Apex Controller name what you like I named it TTL_Lesson, with your logic

public class TTL_Lesson{

//Define your variables
public class OppStageHolder {
    public String OPP {get; set;}
    public Integer TTL_Opp {get; set;}
//Empty Array    
public OppStageHolder (){}
}
//Results will be placed within this List
public List queryResults{ get; set; }

//Your Page
public PageReference TTL() {

AggregateResult[] groupedResults = [SELECT StageName, 

     Count(Name) ce FROM Opportunity 

     GROUP BY StageName];  
System.Debug('zzavg ' + groupedResults.size());
//Define your List
queryResults = new List();

for (AggregateResult ard : groupedResults)  {    
    OppStageHolder myObject = new OppStageHolder();    
    myObject.OPP = String.valueOf(ard.get('StageName'));    
    myObject.TTL_Opp = (Integer) ard.get('ce');         
    queryResults.add(myObject);    
}
return Page.TTL;
}

}

Now create your VF Page to call this and display it whenever the user clicks on this page:

<apex:page controller="TTL_Lesson" action="{!TTL}" showHeader="false" sidebar="false">
    <apex:dataTable value="{!queryResults}" var="a" id="theTable" border="2" cellpadding="1" cellspacing="1" bgcolor="#A9D0F5" >
                <apex:column >
                        <apex:facet name="header">Stage</apex:facet>
                        <apex:outputText value="{!a.OPP}"/>
                </apex:column>               
                <apex:column >
                        <apex:facet name="header">&nbsp;&nbsp;&nbsp;Count</apex:facet>
                        <apex:outputText value="{!a.TTL_Opp}"/>
                </apex:column>
    </apex:dataTable>
</apex:page>

End result is the image on top