更新表中字段的所有记录，该表的值仅在另一个表中

Question

我有表A：

+---------------+------------+-------+-------------+
| name          | id_product | price | price_medium|
+---------------+------------+-------+-------------+
| phone         |         1  |   300 |         300 |
| mouse         |         2  |    50 |          75 |
| phone         |         1  |   250 |         300 |
| keyboard      |         3  |   100 |         100 |
| mouse         |         2  |   100 |          75 |
| phone         |         1  |   350 |         300 |
+---------------+------------+------+--------------+

表B中的表是一个临时表，每次购买产品时都会添加产品，然后将其删除。 发送后，我想更新表A中我在表B中具有product_id作为添加项的“ price_medium”列。

+---------------+------------+-------+-------------+
| name          | id_product | price | price_medium|
+---------------+------------+-------+-------------+
| phone         |         1  |   100 |         220 |
| mouse         |         2  |   125 |          92 |
| phone         |         1  |   100 |         220 |
+---------------+------------+------+--------------+

最终结果将在表A中

+---------------+------------+-------+-------------+
| name          | id_product | price | price_medium|
+---------------+------------+-------+-------------+
| phone         |         1  |   300 |         220 |
| mouse         |         2  |    50 |          92 |
| phone         |         1  |   250 |         220 |
| keyboard      |         3  |   100 |         100 |
| mouse         |         2  |   100 |          92 |
| phone         |         1  |   350 |         220 |
+---------------+------------+------+--------------+

Answer 1

• 您可以使用Inner Join在两个表之间进行id_product
• 使用Set更新表A中的price_medium（等于表B中的price_medium）

尝试：

UPDATE tableA AS tA
JOIN tableB AS tB ON tB.id_product = tA.id_product 
SET tA.price_medium = tB.price_medium