Sample Code:

Visualforce page:

<apex:page controller="Graph" >
    <apex:pageblock title="Members and their Years of experience" >
        <apex:chart height="250" width="350" data="{!pieData}">
            <apex:pieSeries tips="true" dataField="data" labelField="name"/>
            <apex:legend position="bottom"/>
        </apex:chart>
    </apex:pageblock>
                       
    <apex:pageblock title="Members and their Years of experience" >
        <apex:chart height="250" width="350" data="{!pieData}">
            <apex:axis type="Numeric" position="left" fields="data" title="Years of experience"/>   
            <apex:axis type="Category" position="bottom" fields="name" title="Member"/>           
            <apex:barSeries orientation="vertical" axis="left" xField="name" yField="data"/>
        </apex:chart>
    </apex:pageblock>           
</apex:page>

Apex Controller:

public with sharing class Graph
{ 
    public List<PieWedgeData> getPieData()
    { 
        List<PieWedgeData> data = new List<PieWedgeData>();
        List<Member__c> memb = new List<Member__c>(); 
       
        String sql = 'SELECT Name, Year_s_Of_Experience__c FROM Member__c';
        memb = Database.Query(sql);
        for(Member__c temp:memb)
        {          
            data.add(new PieWedgeData(temp.Name,temp.Year_s_Of_Experience__c));
        }
        return data; 
    } 
   
    // Wrapper class 
    public class PieWedgeData
    { 
        public String name { get; set; } 
        public Decimal data { get; set; } 
       
        public PieWedgeData(String name, Decimal data)
        { 
            this.name = name; 
            this.data = data; 
        } 
    } 
}

Output: