</>
sqladvanced

Subquery - Technique 18

Use subqueries

sql
SELECT u.id, u.email
FROM users u
WHERE EXISTS (
  SELECT 1
  FROM orders o
  WHERE o.user_id = u.id
    AND o.created_at >= now() - interval '30 days'
);

Use Cases

  • database operations
  • data management

Tags

#sql#database#subquery

Related Snippets

Similar patterns you can reuse in the same workflow.

sqlintermediate

Subquery Patterns — Scalar, Correlated, Derived

Common subquery patterns including scalar, correlated, and derived table subqueries.

Best for: complex filtering

#sql#subquery
sqlbeginner

View - Technique 1

Create and manage database views

Best for: database operations

#sql#database
sqlintermediate

Index - Technique 2

Create and optimize database indexes

Best for: database operations

#sql#database
sqladvanced

Trigger - Technique 3

Create triggers for automatic actions

Best for: database operations

#sql#database