Question

我正在尝试计算product_id的出现次数。这是我的查询返回10个产品，但不是根据product_id的出现次数。

SELECT name, category_id, product_id 
FROM product, notification 
WHERE type='product_consumed' OR type='product_rate' AND product.id = notification.product_id AND category_id="1" 
GROUP BY product_id ORDER BY product.category_id ASC LIMIT 10

我试着像这样计算product_id的出现次数，但它会给我带来不好的结果，

SELECT name, category_id, product_id, COUNT(*) AS most_viewed 
FROM product, notification 
WHERE type='product_consumed' OR type='product_rate' AND product.id = notification.product_id AND category_id=".$cat." 
GROUP BY product_id ORDER BY product.category_id ASC, most_viewed DESC LIMIT 10

我希望有这样的SQL响应：

产品类别|产品名称|观看次数

由于

Answer 1

试试这个，你缺少一组括号

SELECT name, category_id, product_id, COUNT(*) AS most_viewed 
FROM product, notification 
WHERE (type='product_consumed' OR type='product_rate') AND product.id = notification.product_id AND category_id=".$cat." 
GROUP BY product_id 
ORDER BY product.category_id ASC, most_viewed DESC LIMIT 10

如何在我的SQL查询中使用COUNT

1 个答案: