Generate a BI-style revenue report with SQL, covering MRR, ARR, churn, and active subscriptions using AI2sql. 来源：https://prompts.chat/prompts/cmj7789uu0004v20r1fq7z2p0
Generate a monthly revenue performance report showing MRR, number of active subscriptions, and churned subscriptions for the last 6 months, grouped by month.
