SQL Consecutive Sending Days

Write a SQL query using window functions to identify users who have sent emails on consecutive days.

Treat multiple emails from the same user on one calendar date as a single sending day. Exclude records with a missing user or timestamp.

Output

1. One row per user and consecutive date pair
2. Columns: user_id, previous_sent_date, sent_date, and days_between
3. Include only pairs exactly one calendar day apart
4. Order by user_id, then sent_date ascending