Intermediate 15 min read

Parent-to-Child and Child-to-Parent Queries

By the end of this lesson, you'll be able to:

  • Write a child-to-parent query using dot notation
  • Write a parent-to-child query using a nested subquery

Prerequisites: None — this is the first lesson in the course.

Child-to-parent: dot notation

A child record has exactly one parent, so you can traverse the relationship with simple dot notation:

SELECT Id, Account.Name FROM Contact

Dot notation can chain across more than one level — Account.Owner.Name walks from a Contact up to its Account and then to that Account's owning User.

Parent-to-child: nested subqueries

A parent can have many children, so a single dotted field wouldn't make sense — instead, a nested subquery inside parentheses returns the related list:

SELECT Id, (SELECT Id, LastName FROM Contacts) FROM Account

The subquery uses the plural relationship name (Contacts) for standard relationships, or a custom relationship name ending in __r for custom objects.

A parent query with a nested child subquery

SELECT Id, Name, (SELECT Id, LastName FROM Contacts)
FROM Account
WHERE Industry = 'Technology'

The nested SELECT returns each matching Account's related Contacts as a child list — accessible in Apex via account.Contacts after the query runs.

Exercise

Write a SOQL query that returns each Opportunity's Id and Name, along with its parent Account's Name.

Show hint

Use dot notation: Account.Name

SOQL

Parent-to-Child and Child-to-Parent Queries — Quick Check

1. Which query direction requires a nested subquery instead of dot notation?

2. Dot notation can chain across more than one relationship level, e.g. Account.Owner.Name.

3. Why can't you use dot notation to go from a parent down to its children?

Log in to submit the quiz and save your score.

My Notes

Log in to keep private notes on this lesson.

Questions about this lesson

No questions yet — be the first to ask.

Log in to ask a question about this lesson.

Summary

Child-to-parent queries traverse a relationship with dot notation since a child has exactly one parent; parent-to-child queries use a nested subquery since a parent can have many children.

Log in to track progress
Semi-Joins and Anti-Joins →