Triggers IN Salesforce

Triggers

Trigger:

Apex can be invoked through the use of triggers. A trigger is Apex code that executes before or after the following types of

operations:

• insert

• update

• delete

• merge

• upsert

• undelete

Triggers can be divided into two types:

• Before triggers can be used to update or validate record values before they are saved to the database.

Ø  The first being that you can perform data validation and reject a record before it is committed to the database, meaning there is no cost to performance by the system having to roll back an update. Second, you can update fields or set default values for a record without having to initiate another DML command.

Ø  For example the code below illustrates setting a default value on a record. No DML required.

trigger beforetriggerex on Account (Before insert,before update) {

   

  //setting default values in account

    for(Account a : Trigger.new){

     a.rating = 'hot';

     }

    

     // setting  validation rules

     for(account a: trigger.new){

     if(a.type == 'prospect'){

       a.type.adderror('change account type');

     }

     }

    

     //fields update

     for(account a : trigger.new){

     if(a.phone != null){

       a.fax = a.phone;

       a.website = 'www.salesforce.com';

     }

    

     }

       

}

• After triggers can be used to access field values that are set by the database (such as a record's Id or lastUpdated field), and to affect changes in other records.

trigger createNewAccountOpportunity on Account (after insert) { 

    List<Opportunity> listOpportunities = new List<Opportunity>();

    for (Account a : trigger.new) {

        Opportunity o= new Opportunity();

        o.Name = a.Name;

        o.AccountId = a.Id;

        o.StageName= 'prospecting';

        o.CloseDate = System.today() + 30;

       listOpportunities.add(o);

    }

 insert listOpportunities ;

}