DML

• [ ] Database.insert(records,allOrNone);
• [ ] Database.update(records,allOrNone);
• [ ] Database.delete(recordIds,AllOrNone);
• [ ] Database.undelete(recordIds,AllOrNone);
• [ ]

// Create the list of sObjects to insert
List<Account> acctList = new List<Account>();
acctList.add(new Account(Name='Acme1'));
acctList.add(new Account(Name='Acme2'));

// DML statement
Database.SaveResult[] srList = Database.insert(acctList, false);

// Iterate through each returned result
for (Database.SaveResult sr : srList) {
    if (sr.isSuccess()) {
        // Operation was successful, so get the ID of the record that was processed
        System.debug('Successfully inserted account. Account ID: ' + sr.getId());
    }
    else {
        // Operation failed, so get all errors                
        for(Database.Error err : sr.getErrors()) {
            System.debug('The following error has occurred.');                    
            System.debug(err.getStatusCode() + ': ' + err.getMessage());
            System.debug('Account fields that affected this error: ' + err.getFields());
        }
    }
}

setSavePoint and Rollback

Account a = new Account(Name = 'xxx'); insert a;
System.assertEquals(null, [SELECT AccountNumber FROM Account WHERE Id = :a.Id].
                           AccountNumber);

// Create a savepoint while AccountNumber is null
**Savepoint sp = Database.setSavepoint();**

// Change the account number
a.AccountNumber = '123';
update a;
System.assertEquals('123', [SELECT AccountNumber FROM Account WHERE Id = :a.Id].
                             AccountNumber);

// Rollback to the previous null value
**Database.rollback(sp);**
System.assertEquals(null, [SELECT AccountNumber FROM Account WHERE Id = :a.Id].
                            AccountNumber);

Database.QueryLocator (Batch Apex for details.)

public class SearchAndReplace implements Database.Batchable<sObject>{

   public final String Query;
   public final String Entity;
   public final String Field;
   public final String Value;

   public SearchAndReplace(String q, String e, String f, String v){

      Query=q; Entity=e; Field=f;Value=v;
   }

   public Database.QueryLocator start(Database.BatchableContext BC){
      return **Database.getQueryLocator**(query);
   }

   public void execute(Database.BatchableContext BC, List<sObject> scope){
     for(sobject s : scope){
     s.put(Field,Value); 
     }
     update scope;
    }

   public void finish(Database.BatchableContext BC){
   }
}

SOQL

String myTestString = 'TestName';
List<sObject> sobjList = Database.query('SELECT Id FROM MyCustomObject__c WHERE Name = :myTestString');

SOQL Injection