Interview Questions

Salesforce allows multiple triggers per object, but best practice is one trigger per object. When there are multiple triggers, the order of execution is not guaranteed between triggers (though within a single trigger, order of execution applies). Managed packages have their own separate governor limit set for their triggers.

SOQL (Salesforce Object Query Language): Queries a single object and its related objects. Returns sObject records. Used when you know which object to query. SOSL (Salesforce Object Search Language): Searches across multiple objects simultaneously using full-text search index. Returns List<List<SObject>>. Used when you don't know which object has the data or need cross-object search. // SOSL example List<List<SObject>> results = [FIND 'Acme' IN ALL FIELDS RETURNING Account(Id, Name), Contact(Id, Name)];

Semi-join: Returns records where a field value EXISTS in a subquery. Example: SELECT Id FROM Account WHERE Id IN (SELECT AccountId FROM Contact WHERE Email != null) Anti-join: Returns records where a field value does NOT EXIST in a subquery. Example: SELECT Id FROM Account WHERE Id NOT IN (SELECT AccountId FROM Contact)

SELECT AccountId, COUNT(Id) cnt FROM Contact GROUP BY AccountId ORDER BY COUNT(Id) DESC LIMIT 1

SELECT Id, Name FROM Account WHERE Id NOT IN (SELECT AccountId FROM Contact WHERE AccountId != null)

SELECT StageName, COUNT(Id) cnt FROM Opportunity GROUP BY StageName

SELECT AccountId, COUNT(Id) cnt FROM Contact GROUP BY AccountId HAVING COUNT(Id) > 3

SELECT Amount FROM Opportunity ORDER BY Amount DESC LIMIT 1 OFFSET 1

// Parent-to-child (inner query - standard objects use relationship name) SELECT Id, Name, (SELECT Id, FirstName, LastName FROM Contacts) FROM Account // Child-to-parent (dot notation) SELECT Id, FirstName, Account.Name, Account.BillingCity FROM Contact // Custom object child-to-parent (use __r instead of __c) SELECT Id, Name, Account__r.Name FROM Invoice__c

SELECT Phone, COUNT(Id) cnt FROM Lead GROUP BY Phone HAVING COUNT(Id) > 1

SELECT UserRole.Name FROM User WHERE Id = :userId

SELECT Id, Name FROM UserRole WHERE Id NOT IN (SELECT UserRoleId FROM User WHERE UserRoleId != null)

SELECT Id, Name FROM Account WHERE IsDeleted = true ALL ROWS

SELECT Id FROM Lead WHERE CreatedDate >= LAST_N_YEARS:4

SOSL is the best approach — it can search across multiple objects in one query: List<List<SObject>> results = [FIND 'manjunath@gmail.com' IN EMAIL FIELDS RETURNING Contact(Id, Email), Lead(Id, Email)];

An External ID is a custom field marked as an External ID — it gets indexed and can be used for upsert operations by matching the external system's identifier. Use cases: (1) Upsert records using an external key instead of Salesforce Id; (2) Mapping records during data migration from external systems; (3) Can be used in relationship fields for foreign key lookups in Data Loader.