题解 | #获取指定客户每月的消费额#

SELECT DATE_FORMAT(C.t_time,'%Y-%m') AS time,SUM(C.t_amount) AS total FROM (SELECT * FROM (SELECT * FROM trade)A JOIN (SELECT * FROM customer)B ON A.t_cus=B.c_id WHERE DATE_FORMAT(A.t_time,'%Y-%m')>='2023-01' AND B.c_name='Tom' AND A.t_type=1) C  GROUP BY DATE_FORMAT(C.t_time,'%Y-%m') ORDER BY DATE_FORMAT(C.t_time,'%Y-%m')