Write a SQL query to calculate the month-over-month retention rate of users signing up for a free trial of Grafana Cloud. Treat a user as retained when they have at least one usage event in the calendar month immediately after their signup month.
signup_month, retention_month, cohort_users, retained_users, and retention_rate.retention_rate as a percentage rounded to two decimal places, ordered by signup_month ascending.| Column | Type | Description |
|---|---|---|
| user_idPK | INT | Unique Grafana Cloud user identifier |
| VARCHAR(255) | User email address | |
| trial_type | VARCHAR(20) | Trial or subscription type |
| trial_started_at | TIMESTAMP | Timestamp when the trial began |
| Column | Type | Description |
|---|---|---|
| event_idPK | INT | Unique usage event identifier |
| user_id | INT | User associated with the usage event |
| occurred_at | TIMESTAMP | Timestamp when the usage event occurred |
| event_name | VARCHAR(100) | Name of the Grafana Cloud activity |