Sample Code:
SELECT Id, ValidationName, Description, EntityDefinition.DeveloperName, ErrorDisplayField, ErrorMessage FROM ValidationRule Where EntityDefinition.DeveloperName='<Object Name>' And Active = true
Note: To query use Tooling API
Sample Code:
boolean isPersonAccount = Schema.SObjectType.Account.fields.getMap().containsKey('isPersonAccount');
system.debug('isPersonAccount-' + isPersonAccount);
Sample Code:
String browserInfo = ApexPages.currentPage().getHeaders().get('User-Agent');
system.debug('Browser Info-' + browserInfo);
| Feature | Custom Objects | External Objects |
|---|---|---|
| Data is stored in your Salesforce org | Yes | No |
| Read | Yes | Yes |
| Write | Yes | Yes (limited) |
| Tabs, layouts | Yes | Yes |
| Visualforce | Yes | Yes |
| Field-level security | Yes | Yes |
| Sharing | Yes | No |
| REST and SOAP API | Yes | Yes |
| SOQL | Yes | Yes (limited) |
| Search and SOSL | Yes | Yes (pass-through) |
| Formula fields | Yes | Not Yet |
| Workflow, triggers | Yes | Not Yet |
| Reports and analytics | Yes | Not Yet |
| Chatter | Yes | Yes (no field tracking) |
Here is a sample Rollup Summary calculation trigger for Lookup relationship. In below example I’m using Account object as parent and Contact object as child.
I’m updating Account object Account record field Number_of_Contacts__c with Count of all related Contact records.
Apex Trigger:
trigger ContactTrigger on Contact (after insert, after update, after delete, after undelete) {
Set<Id> accountIds = new Set<Id>();
if(trigger.isInsert || trigger.isUpdate || trigger.isUndelete){
for(Contact con:trigger.new){
if(con.AccountId != null){
accountIds.add(con.AccountId);
}
}
}
if(trigger.isUpdate || trigger.isDelete){
for(Contact con:trigger.old){
if(con.AccountId != null){
accountIds.add(con.AccountId);
}
}
}
if(!accountIds.isEmpty()){
List<Account> accList = [SELECT Id, Number_of_Contacts__c, (SELECT Id FROM Contacts)
FROM Account WHERE Id IN : accountIds];
if(!accList.isEmpty()){
List<Account> updateAccList = new List<Account>();
for(Account acc:accList){
Account objAcc = new Account(Id = acc.Id, Number_of_Contacts__c = acc.Contacts.size());
updateAccList.add(objAcc);
}
if(!updateAccList.isEmpty()){
update updateAccList;
}
}
}
}