Mysql 从表中选择并更新另一个表SQL

我正在尝试从“reviews”表中获取“business\u id”和“rating”，其中“review\u id”是$ApproveView

然后使用从“评论”中检索到的评级更新“业务详细信息”中的“评级”，其中“业务id”等于检索到的评级

我有两个疑问,

SELECT business_id, rating FROM reviews WHERE review_id = '$approveReviewID';

UPDATE business_details SET rating = rating + $rating WHERE business_id = '$businessID';

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有没有办法将这些查询合并为一个查询？

是的，您可以使用update join语法：

UPDATE business_details bd
JOIN   reviews r ON bd.business_id = r.business_id
SET    bd.rating = bd.rating + r.rating
WHERE  r.review_id = '$approveReviewID'

在from子句中使用简单的“内部联接”联接两个表

UPDATE  bd
SET     rating = bd.rating + rvs.rating
FROM    reviews rvs
        INNER JOIN business_details bd ON db.business_id = rvs.business_id
WHERE   rvs.review_id = '$approveReviewID'