我可以根据对每一行的选择来运行更新查询吗？这是我想尝试的:
UPDATE adverts SET advert_visits = (SELECT COUNT(earning_id) FROM earnings WHERE earning_advert_id = 1093)
但我不确定如何让选择应用广告表中每一行的正确 advert_id？
或者这可能只是一个完全无效的语法，我不确定。
最佳答案
只需简单地引用更新后的表:
UPDATE adverts
SET advert_visits = (
SELECT COUNT(earning_id)
FROM earnings
WHERE earning_advert_id = adverts.advert_id
)
关于mysql - 根据select更新MySQL表，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/35023501/