How can I manipulate records with DML in Salesforce?

DML operations allow you to modify records one at a time or in batches. DML are the actions which are performed in order to perform insert, update, delete, upsert, delete & undelete.  You can perform DML operations either on a single sObject, or in bulk on a list of sObjects.

Followings are DML actions

•      insert: Use this statement to create the records of sObject.

•      update: Use this statement to update the existing records of sObject.

•      upsert: Use this statement to create the new record or update the existing records on the basis of  Id or external field.

•      delete : Use this statement to delete the existing record

•      undelete : Use this statement to restore the records from Organization recycle bin.

•      merge : Use this statement to merge the records of same sObject type by deleting other and re-parenting the related records. You can use up to 3 records to merge.

Sample Code

Account[] acctsList = [SELECT Id, Name, BillingCity

FROM Account WHERE BillingCity = 'Bombay'];

for (Account a : acctsList) {

a.BillingCity = 'Mumbai';

}

Account newAcct = new Account(Name = 'Acme', BillingCity = 'San Francisco');

acctsList.add(newAcct);

try {

upsert acctsList;

} catch (DmlException e) {

System.debug(e.ErrorMessage());

// Process exception here

}