Writes and debugs Apex code, builds Lightning Web Components, optimizes SOQL queries, implements triggers, batch jobs, platform events, and integrations on the Salesforce platform. Use when developing Salesforce applications, customizing CRM workflows, managing governor limits, bulk processing, or setting up Salesforce DX and CI/CD pipelines.
Load detailed guidance based on context:
| Topic | Reference | Load When |
|---|---|---|
| Apex Development | references/apex-development.md | Classes, triggers, async patterns, batch processing |
| Lightning Web Components | references/lightning-web-components.md | LWC framework, component design, events, wire service |
| SOQL/SOSL | references/soql-sosl.md | Query optimization, relationships, governor limits |
| Integration Patterns | references/integration-patterns.md | REST/SOAP APIs, platform events, external services |
| Deployment & DevOps | references/deployment-devops.md | Salesforce DX, CI/CD, scratch orgs, metadata API |
Database.update(scope, false) for partial success// CORRECT: collect IDs, query once outside the loop
trigger AccountTrigger on Account (before insert, before update) {
AccountTriggerHandler.handleBeforeInsert(Trigger.new);
}
public class AccountTriggerHandler {
public static void handleBeforeInsert(List<Account> newAccounts) {
Set<Id> parentIds = new Set<Id>();
for (Account acc : newAccounts) {
if (acc.ParentId != null) parentIds.add(acc.ParentId);
}
Map<Id, Account> parentMap = new Map<Id, Account>(
[SELECT Id, Name FROM Account WHERE Id IN :parentIds]
);
for (Account acc : newAccounts) {
if (acc.ParentId != null && parentMap.containsKey(acc.ParentId)) {
acc.Description = 'Child of: ' + parentMap.get(acc.ParentId).Name;
}
}
}
}
// INCORRECT: SOQL inside loop — governor limit violation
trigger AccountTrigger on Account (before insert) {
for (Account acc : Trigger.new) {
Account parent = [SELECT Id, Name FROM Account WHERE Id = :acc.ParentId]; // BAD
acc.Description = 'Child of: ' + parent.Name;
}
}
public class ContactBatchUpdate implements Database.Batchable<SObject> {
public Database.QueryLocator start(Database.BatchableContext bc) {
return Database.getQueryLocator([SELECT Id, Email FROM Contact WHERE Email = null]);
}
public void execute(Database.BatchableContext bc, List<Contact> scope) {
for (Contact c : scope) {
c.Email = '[email protected]';
}
Database.update(scope, false); // partial success allowed
}
public void finish(Database.BatchableContext bc) {
// Send notification or chain next batch
}
}
// Execute: Database.executeBatch(new ContactBatchUpdate(), 200);
@IsTest
private class AccountTriggerHandlerTest {
@TestSetup
static void makeData() {
Account parent = new Account(Name = 'Parent Co');
insert parent;
Account child = new Account(Name = 'Child Co', ParentId = parent.Id);
insert child;
}
@IsTest
static void testBulkInsert() {
Account parent = [SELECT Id FROM Account WHERE Name = 'Parent Co' LIMIT 1];
List<Account> children = new List<Account>();
for (Integer i = 0; i < 200; i++) {
children.add(new Account(Name = 'Child ' + i, ParentId = parent.Id));
}
Test.startTest();
insert children;
Test.stopTest();
List<Account> updated = [SELECT Description FROM Account WHERE ParentId = :parent.Id];
System.assert(!updated.isEmpty(), 'Children should have descriptions set');
System.assert(updated[0].Description.startsWith('Child of:'), 'Description format mismatch');
}
}
// Selective query — use indexed fields in WHERE clause
List<Opportunity> opps = [
SELECT Id, Name, Amount, StageName
FROM Opportunity
WHERE AccountId IN :accountIds // indexed field
AND CloseDate >= :Date.today() // indexed field
ORDER BY CloseDate ASC
LIMIT 200
];
// Relationship query to avoid extra round-trips
List<Account> accounts = [
SELECT Id, Name,
(SELECT Id, LastName, Email FROM Contacts WHERE Email != null)
FROM Account
WHERE Id IN :accountIds
];
<!-- counterComponent.html -->
<template>
<lightning-card title="Counter">
<div class="slds-p-around_medium">
<p>Count: {count}</p>
<lightning-button label="Increment" onclick={handleIncrement}></lightning-button>
</div>
</lightning-card>
</template>
// counterComponent.js
import { LightningElement, track } from 'lwc';
export default class CounterComponent extends LightningElement {
@track count = 0;
handleIncrement() {
this.count += 1;
}
}
<!-- counterComponent.js-meta.xml -->
<?xml version="1.0" encoding="UTF-8"?>
<LightningComponentBundle xmlns="http://soap.sforce.com/2006/04/metadata">
<apiVersion>59.0</apiVersion>
<isExposed>true</isExposed>
<targets>
<target>lightning__AppPage</target>
<target>lightning__RecordPage</target>
</targets>
</LightningComponentBundle>