Question

我想从几个INNER JOINS更新表INVENTAR中的列。我有以下几点：
表INVENTAR列PRODUCT_ID，CATEGORY 表格PRODUCT_TO_CATEGORY包含PRODUCT_ID，CATEGORY_ID列表CATEGORY_DESCRIPTION列CATEGORY_ID，NAME

我希望NAME列更新CATEGORY列。这是我的代码：

UPDATE inventar
   SET inventar.category=category_description.name
  FROM inventar
       INNER JOIN product_to_category 
             ON product_to_category.product_id=inventar.product_id
       INNER JOIN category_description 
             ON category_description.category_id=product_to_category.category_id

Answer 1

正确的MySQL语法是：

UPDATE inventar i INNER JOIN
       product_to_category ptc
       ON ptc.product_id = i.product_id INNER JOIN
       category_description cd
       ON cd.category_id = ptc.category_id
   SET i.category = cd.name;

您的语法看起来更适合SQL Server或Postgres。

来自两个INNER JOINS的更新

1 个答案: