如何根据旧表中的3列更新和新表？

Question

我有两张桌子：

1. new_product包含列：

   id_product, 
   id_category, 
   id_combination, 
   id_feature, 
   whole_sale_price, 
   retail_price,
   

2. old_product包含列：

   id_product, 
   id_category, 
   id_combination, 
   id_feature, 
   whole_sale_price, 
   retail_price,
   

如何使用来自{{1}的whole_sale_price和retail_price列的值更新new_product上的whole_sale_price和retail_price列中的数据使用密钥old_product，id_category和id_combination？

Answer 1

一般来说，您可以按如下方式编写：

UPDATE
  table1 AS target,
  (SELECT column1, column2 FROM table2) AS source
SET
  target.column3 = source.column1
WHERE
  target.column4 = source.column2

Answer 2

如果您想更新whole_sale_price和retail_price，可以使用此查询：

UPDATE new_product as newP
JOIN old_product as oldP
ON newP.id_category = oldP.id_category AND
   newP.id_combination = oldP.id_combination AND
   newP.id_feature = oldP.id_feature
SET newP.whole_sale_price = oldP.whole_sale_price,
newP.retail_price = oldP.retail_price