mysql count函数不能正常工作

Question

我正在尝试计算购买前一天发生的产品页面浏览量。我用过这个查询

SELECT 
    p.customer_id AS cid,
    p.product_id AS product,
    p.revenue,
    p.order_id,
    p.datetime,
    pv.customer_id,
    pv.product_id,
    pv.datetime AS date,
    od.name2,
    COUNT(pv.product_id)
FROM
    customer_profiles.purchase p
        LEFT JOIN
    customer_profiles.product_view pv ON pv.customer_id = p.customer_id
        LEFT JOIN
    opencart.product_description od ON od.product_id = p.product_id
        AND od.language_id = 2
WHERE
    pv.datetime BETWEEN DATE_SUB(DATE(p.datetime),
        INTERVAL 1 DAY) AND DATE(p.datetime)
        AND pv.product_id = p.product_id
GROUP BY pv.product_id

但是计数不正常它会给出一个随机数。我已经使用过count（DISTINCT pv.product_id），遗憾的是它对我来说也不起作用？