我有以下表格:从多个表中检索数据 - SQL
表搜索:
Date Product Search_ID
2017-01-01 Nike 101
2017-01-01 Reebok 292
2017-01-01 Nike 103
2017-01-01 Adidas 385
2017-01-02 Nike 284
表采购
Date Product Total_sale
2017-01-01 Adidas 4
2017-01-01 Nike 1
2017-01-01 Adidas 2
2017-01-02 Nike 3
每件产品可以在同一天之内多行。当天产品的购买总数=总和(total_sale)
我需要找出每件产品每天的购买比率,即购买数量/搜索次数。
为了参考,对于耐克上2017-01-01
,搜索的总数是702
而购买的总数为47
,给我尝试的4 7/702 = 0.0669
购买比率:
select t1.product, sum(t1.Total_sale), count(t2.Search_ID)
from db.purchases t1 join db.searches
on t1.date = t2.date and t1.product = t2.product
where t1.date = '2017-01-01' and t1.product = 'Nike'
group by t1.product, t1.date
;
,这给我一个奇怪的结果:
product | sum | count
----------+-------+-------
Nike | 32994 | 32994
......我在做什么错在这里?