小明需要处理某支付app会在客户端打印的日志。其中客户端有表user_client_log(trace_id,uid,logtime,step,product_id,pay_method)分别代表trace_id订单号,uid(用户id)、logtime(客户端事件发生时间)、step(客户端步骤)、product_id(商品id)、pay_method(支付方式), 其中有product_info(product_id,price,type,product_name)分别代表product_id商品id、price商品价格、type商品类型、product_name商品名称(表中数据已去重)。 【问题】需要小明展示商品销售额排名分布前2的的商品的商品名称(product_name),以销售额的逆序排列返回。 【知识点】关联查询、条件查询、窗口函数、聚合函数、排序函数 【示例结果】返回两列:商品名称、商品价格 【示例解析】 根据商品名称分组聚合统计销售额,最后以销售额进行排名,返回前两个商品的销售额度和销售额 注: 只有select步骤的数据有pay_method字段; 如果select中pay_method为''则以error标记pay_method为脏数据; 无需考虑返回为空的异常处理
示例1

输入

DROP TABLE IF EXISTS `user_client_log`;
CREATE TABLE IF NOT EXISTS `user_client_log`(
    trace_id varchar(255) NOT NULL,
    uid varchar(32) DEFAULT NULL,
    logtime varchar(32) DEFAULT NULL,
    step varchar(32) DEFAULT NULL,
    product_id varchar(32) DEFAULT NULL,
    pay_method varchar(32) DEFAULT NULL,
    UNIQUE uni_trace(trace_id,step)
);
DROP TABLE IF EXISTS `product_info`;
CREATE TABLE IF NOT EXISTS `product_info`(
    product_id varchar(32) NOT NULL,
    price int(32) DEFAULT 0,
    type varchar(32) NOT NULL,
    product_name varchar(255) NOT NULL,
    UNIQUE uni_product(product_id)
);
INSERT IGNORE `product_info` VALUES 
    ('p100',100,'shoes','anta'),
    ('p599',5000,'telephone','huawei'),
    ('p233',2,'water','wahaha');
INSERT IGNORE `user_client_log` VALUES
    ('0001','user_0001','2022-01-01 00:00:00','select','p100','wx'),
    ('0001','user_0001','2022-01-01 00:00:04','order','p100',''),
    ('0001','user_0001','2022-01-01 00:00:04','start','p100',''),
    ('0001','user_0001','2022-01-01 00:00:08','end','p100',''),
    ('0002','user_0002','2022-01-01 10:00:00','select','p599','alipay'),
    ('0002','user_0002','2022-01-01 10:00:00','order','p599',''),
    ('0002','user_0002','2022-01-01 10:00:01','start','p599',''),
    ('0002','user_0002','2022-01-01 10:00:10','failed','p599',''),
    ('0003','user_0003','2022-01-01 10:00:00','select','p599','alipay'),
    ('0003','user_0003','2022-01-01 10:00:00','order','p599',''),
    ('0004','user_0004','2022-01-01 10:00:00','select','p100','wx'),
    ('0004','user_0004','2022-01-01 10:00:00','order','p100',''),
    ('0004','user_0004','2022-01-01 10:00:01','start','p100',''),
    ('0005','user_0005','2022-01-01 10:00:00','select','p100','meituan'),
    ('0005','user_0005','2022-01-01 10:00:00','order','p100',''),
    ('0005','user_0005','2022-01-01 10:00:01','start','p100',''),
    ('0006','user_0006','2022-01-01 10:00:00','select','p599','alipay'),
    ('0006','user_0006','2022-01-01 10:00:00','order','p599',''),
    ('0006','user_0006','2022-01-01 10:00:01','start','p599','');

输出

huawei|15000
anta|300
加载中...