```sql WITH customer_avg AS ( -- 1. 先计算每个客户的总贷款金额 SELECT c.city, c.customer_id, SUM(la.loan_amount) AS customer_total_loan FROM loan_applications la INNER JOIN customers c ON la.customer_id = c.customer_id GROUP BY c.city, c.customer_id ), city_loan_stats AS ( -- 2. 计算每个城市每个贷款类型的申请次数 SELECT c.city, ...
