To fetch data from Controller and display it in Visualforce page without using button, retrieve the record in the constructor.


Sample code:


Visualforce page:

<apex:page controller=”Sample” >
    <apex:form >
       <apex:pageblock id=”account” title=”Account Details(Standard Object)” >
            <apex:pageblockTable value=”{!acc}” var=”a”>
                <apex:column value=”{!a.Name}”/>
                <apex:column value=”{!a.AccountNumber}”/>
            </apex:pageblockTable>
        </apex:pageblock>
       <apex:pageblock id=”member” title=”Member Details(Custom Object)”>
            <apex:pageblockTable value=”{!mem}” var=”m”>
                <apex:column value=”{!m.Name}”/>
            </apex:pageblockTable>         
        </apex:pageblock>          
    </apex:form>
</apex:page>


Controller:


public with Sharing class Sample
{   
    public List<Account> acc {get;set;}
    public List<Member__c> mem {get;set;}   
      
    public sample()
    {
        acc = [SELECT Name, AccountNumber FROM Account];
        mem = [SELECT Name FROM Member__c];
    }
}


Output: