Optimize count calculation

[tw2066]

Optimize the group by count calculation

[tw2066]

Prevents groupby from returning too many numbers, and optimizes the number directly to the database

Before optimization, you need to calculate the quantity

SELECT count() as `count` FROM `test` WHERE `id` != 12 GROUP BY `goods_id`

After optimization, directly return the quantity

SELECT count() as `count` FROM (SELECT `goods_id` FROM `test` WHERE `id` != 12 GROUP BY `goods_id`)