Write a PostgreSQL query to compare month-1 retention across monthly rider signup cohorts. A rider belongs to the cohort of their signup_date month, and is considered retained if they complete at least one ride in the next calendar month. Return cohort month, cohort size, retained riders, and retention rate.
| Column | Type | Description |
|---|---|---|
| rider_id | ||
| rider_name | ||
| signup_date | ||
| city |
| Column | Type | Description |
|---|---|---|
| ride_id | ||
| rider_id | ||
| ride_date | ||
| status | ||
| fare_amount |
status = 'completed'.