Trigger Bad example with try/catch

gistfile1.txt

trigger CaseTrigger on Case (after insert) {
 
 system.debug('***CaseTrigger begin');

 // In this example trigger we are simply wanting to flag at the Account level
 // that the Account has a Case linked to it, which is a lookup field on Case
 // so we wouldn't be able to do a rollup count.
 // In reality we would also want to track deletes of Cases but that is skipped 
 // for demonstration purposes.
  
 // bulk map of accounts that we need to update
 map<Id, Account> accountsForUpdateMap = new map<Id, Account>();

 // find accounts to update
 for(Case c : trigger.new){
  // if this case is linked to an account and we've not already tagged this account
  if(c.AccountId != null && !accountsForUpdate.containsKey(c.AccountId))
   // add this account to the map
   accountsForUpdate.put(c.AccountId, new Account(Id = c.AccountId, HasACase__c = true));
 }

 // check to see if we need to perform DML
 if(!accountsForUpdate.isEmpty()){
  try{
   // let's do the DML
   update accountsForUpdate.values();
  } catch(dmlexception e){
   // ************ Assume the ACCOUNT update FAILED ***********
   // If DML failed, ends up here
   system.debug('Error updating account: ' + e);
  }

 }

 // If we get this far in code, something may have failed and been caught above, or everything worked.
 system.debug('Potential Success');

 // If anything were to go wrong in the above DML, since we do have a try/catch the server
 // will NOT automatically rollback the changes. (In this instance the Cases in this trigger
 // WOULD be inserted into the database. This is usually NOT desired since the 
 // Account data is inaccurate.)
 // NO error would show on the calling page or calling code that fired this trigger. 

}