Salesforce: Use Tab in Visualforce Page

Visualforce Page:

<apex:page doctype="html-5.0" standardcontroller="account" tabstyle="account">
    <apex:pageblock title="{!account.Name}">
        <apex:tabpanel id="tabpanel">
         
            <apex:tab label="Account Details" rerender="tabpanel" switchtype="ajax">
            <apex:detail relatedlist="false"></apex:detail>
            </apex:tab>
             
            <apex:tab label="Contacts" rerender="tabpanel" switchtype="ajax">
            <apex:relatedlist list="Contacts"></apex:relatedlist>
            </apex:tab>
             
            <apex:tab label="Opportunities" rerender="tabpanel" switchtype="ajax">
            <apex:relatedlist list="Opportunities"></apex:relatedlist>
            </apex:tab>
             
            <apex:tab label="Cases" rerender="tabpanel" switchtype="ajax">
             <apex:relatedlist list="Cases"></apex:relatedlist>
            </apex:tab>
             
        </apex:tabpanel>
    </apex:pageblock>
</apex:page>

Note: Please pass account id in url e.g.
https://salesforce.com/apex/TabInVisualForcePage?id=0019000001DEV5z

Output:

index

Transaction Control using SavePoint and Rollback in Salesforce

SavePoint and Rollback will help us to maintain transaction for DML statement.
Suppose you  have written multiple lines of DML statements in a try block, If any error occurs during DML Operations, the operation will be rolled back to the most recent save point and the entire transaction will not be aborted.

Savepoint sp;
try{
   sp = Database.setSavepoint();
 
   Account a = new Account();
   a.Name = 'Test Account';
   insert a;
 
   Contact c = new Contact(Account = a.Id);
   c.FirstName = 'Biswajeet';
   c.LastName = 'Samal';
   insert c;
  }
catch(Exception e){
    Database.RollBack(sp);
}

In this example, if any error occurs while inserting the Account ‘a’ or Contact ‘c’, then the entire transaction will be rolled back to SavePoint ‘sp’, as specified in the catch section by Database.Rollback method.

Salesforce: Convert decimal value to integer using apex

If we convert decimal into integer like below code, it will compile without a problem, but at the time of execution, an error will occur.

Decimal mydecval = 15.0;
Integer myintval = Integer.valueOf(mydecval);

So, we should always use decimalvariable.intValue() to convert decimal value into integer.
Here is sample code:

Decimal mydecval = 15.0;
Integer myintval = dmydecval.intValue();

How to get default value of a picklist in apex controller?

String defaultVal = '';
Schema.DescribeFieldResult objDF = Lead.Status.getDescribe();
List<schema.picklistentry> pickVals = objDF.getPicklistValues();        
for (Schema.PicklistEntry pv: pickVals) {
    if (pv.isDefaultValue()) {
        defaultVal = pv.getValue();
    break;
    }    
}
system.debug('Picklist Default value is' + defaultVal);