Learn SALESFORCE-SCRIPTING with Real Code Examples

trigger AccountTrigger on Account (before insert) {
    for(Account acc : Trigger.new) {
        acc.Custom_Field__c = 'New Account';
    }
}

A trigger that updates a custom field when an Account is inserted.

public class DiscountCalculator {
    public static Decimal ApplyDiscount(Decimal price, Decimal percent) {
        return price - (price * percent / 100);
    }
}

A simple Apex class method that calculates discounted price.

global class OpportunityBatch implements Database.Batchable<sObject> {
    global Database.QueryLocator start(Database.BatchableContext BC) {
        return Database.getQueryLocator('SELECT Id FROM Opportunity WHERE StageName = 'Prospecting'');
    }
    global void execute(Database.BatchableContext BC, List<Opportunity> scope) {
        for(Opportunity opp : scope) {
            opp.StageName = 'Closed Won';
        }
        update scope;
    }
    global void finish(Database.BatchableContext BC) {}
}

Batch Apex class to update Opportunity Stage to 'Closed Won'.

trigger ContactEmailTrigger on Contact (after insert) {
    List<Messaging.SingleEmailMessage> emails = new List<Messaging.SingleEmailMessage>();
    for(Contact c : Trigger.new) {
        Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();
        mail.setToAddresses(new String[] {c.Email});
        mail.setSubject('Welcome!');
        mail.setPlainTextBody('Hello ' + c.FirstName + ', welcome to our platform.');
        emails.add(mail);
    }
    Messaging.sendEmail(emails);
}

Send a welcome email when a new Contact is created.

trigger PreventAccountDelete on Account (before delete) {
    for(Account acc : Trigger.old) {
        Integer contactCount = [SELECT COUNT() FROM Contact WHERE AccountId = :acc.Id];
        if(contactCount > 100) {
            acc.addError('Cannot delete account with more than 100 contacts');
        }
    }
}

Prevent deletion of Account records with more than 100 related Contacts.

global class LeadStatusScheduler implements Schedulable {
    global void execute(SchedulableContext sc) {
        List<Lead> leads = [SELECT Id FROM Lead WHERE Status != 'Contacted'];
        for(Lead l : leads) {
            l.Status = 'Contacted';
        }
        update leads;
    }
}

Scheduled Apex to update all Leads' Status to 'Contacted' every night.

trigger CaseOwnerTrigger on Case (before insert) {
    Id queueId = [SELECT Id FROM Group WHERE Name = 'Support Queue' AND Type='Queue' LIMIT 1].Id;
    for(Case c : Trigger.new) {
        c.OwnerId = queueId;
    }
}

Automatically assign new Cases to a default queue.

String objectName = 'Account';
String fieldName = 'Name';
String filterValue = 'Acme';
String query = 'SELECT Id, ' + fieldName + ' FROM ' + objectName + ' WHERE ' + fieldName + ' LIKE '%' + filterValue + '%'';
List<SObject> results = Database.query(query);

Build and execute a dynamic SOQL query based on user input.

trigger AccountChangeLog on Account (after update) {
    List<Account_Log__c> logs = new List<Account_Log__c>();
    for(Account acc : Trigger.new) {
        Account oldAcc = Trigger.oldMap.get(acc.Id);
        if(acc.Name != oldAcc.Name) {
            logs.add(new Account_Log__c(Account__c=acc.Id, Old_Name__c=oldAcc.Name, New_Name__c=acc.Name));
        }
    }
    insert logs;
}

Log Account name changes into a custom object.

List<MySettings__mdt> settings = [SELECT MasterLabel, Threshold__c FROM MySettings__mdt];
for(MySettings__mdt s : settings) {
    System.debug('Threshold for ' + s.MasterLabel + ': ' + s.Threshold__c);
}

Read a custom metadata type to control logic in Apex.