mysql 单表更新和多表更新

mysql更新语句sql

一、单表更新:

UPDATE table  nameSET name.column_name = new_valueWHERE name.column_name = some_value;

二、多表更新:

1.级联更新UPDATE product p, product_price pp  SET pp.price = pp.price * 0.8  WHERE p.productId = pp.productId  AND p.dateCreated < '2014-01-01';2.使用inner Join 或者 left Join更新UPDATE product p  INNER JOIN product_price pp  ON p.productId = pp.productId  SET pp.price = pp.price * 0.8  WHERE p.dateCreated < '2014-01-01';UPDATE product p  LEFT JOIN product_price pp  ON p.productId = pp.productId  SET pp.price = pp.price * 0.8 WHERE p.dateCreated < '2014-01-01';3.关联子查询UPDATE product_price ppSET pp.price = pp.price * 0.8WHERE    pp.productId IN (        SELECT            p.productId        FROM            product p        WHERE            p.dateCreated < '2014-01-01'    );

总结： 个人建议第三种，效率高