Part 43: Inserting Data from Other Tables: INSERT INTO ... SELECT

Copying and transforming data between tables directly in the database engine.

1. Syntax

-- Archive inactive users into an archive table:
INSERT INTO archived_users (user_id, email, archived_at)
SELECT id, email, CURRENT_TIMESTAMP
FROM users
WHERE is_active = FALSE AND last_login < '2023-01-01';

Key Takeaways

• Perform ETL data migration completely in-memory inside the database with INSERT INTO ... SELECT.

In Part 44, we explore Updating Rows with UPDATE & The Danger of Missing WHERE!